The Critical Assessment of Locke and Berkeley Concept of Knowledge

The Critical Assessment of Locke and Berkeley Concept of Knowledge



1.0 Introduction

John Locke gave an account of the object of knowledge. Locke held that even though all we ever have of knowledge is the ideas in the mind, he maintained that at least some of these ideas actually do represent real things in the external world, thereby creating an empirical conception of knowledge and rejection of innate idea. Locke is taking it that experience of the likes of shapes provide us with knowledge of what the categorical shape property is. In this chapter, I will attempt a characterization and articulation the limit, scope and extent of object of knowledge. Locke’s theory will be examined with arguments that emanate from his conception of perception, understanding perceptual knowledge of objects, Lockean arguments for direct realism and Locke’s theory of ideas argument.

1.1 Locke’s Rejection of Innate Ideas

Locke has two main arguments against the innateness of ideas, both speculative and practical. First, he argues, people in fact do not universally hold to these ideas, contrary to what defenders of innate ideas typically claim. This is particularly obvious with the laws of thought, which children and mentally challenged people have no conception of whatsoever. If, therefore, children and idiots have souls, have minds, with those impressions upon them, they must unavoidably perceive them, and necessarily know and assent to these truths. Which since they do not, it is evident that there are no such impressions. For if they are not notions naturally imprinted, how can they be innate? and if they are notions imprinted, how can they be unknown? To say a notion is imprinted on the mind, and yet at the same time to say, that the mind is ignorant of it, and never yet took notice of it, is to make this impression nothing.

1. Locke’s second argument is that it makes no sense to hold that such ideas lie dormant within us and then blossom when we reach a certain age, contrary to what defenders of innate ideas commonly claim. Again, particularly with the laws of thought, children reason perfectly well regarding identity and non-contradiction, yet at the same time are completely incapable of articulating those specific ideas. If these ideas really were innate, then children should be able to verbally express them. As Locke states it, “How many instances of the use of reason may we observe in children, a long time before they have any knowledge of this maxim, ‘That it is impossible for the same thing to be and not to be?

2. Also, it is obvious that may adults have reached the so-called age of reason, such as the illiterate and those from primitive societies, and yet lack these ideas. These people “pass many years, even of their rational age, without ever thinking on this and the like general propositions.”

3. In this vein, Locke offers his causal theory of perception. This causal theory of perception reveals that the world interacts with out perceiving organs and causes our ideas in our minds; Locke’s use of the word idea is very broadly- nearly any mental item can count as an idea, a concept, a memory or even a simple sensation. As such, we may accept that the world causes our ideas about (perceptions of) it. What we then call perception is synonymous with ideas in Lockean conception.

It should, however, be noted that our ideas about reality are different from reality itself; ideas are mental but reality is extra mental. It is, therefore, crucial to examine the connection between the two: perceptions and extra-mental reality in detail. What is the relationship between our ideas and the world?

1.2 What is Perceptual Object?

The object of perception may appear multi-faceted because it is a term that goes beyond visuals or oratory, it could be understood in the psychological state, moral state and even in social settings. However, the conception that is useful in this project is that which relates to philosophical understanding across the different types of perception.

In the words of Corsini:

A common finding across many different kinds of perception is that the perceived qualities of an object can be affected by the qualities of context. If one object is extreme on some dimension, then neighboring objects are perceived as further away from that extreme. “Simultaneous contrast effect” is the term used when stimuli are presented at the same time, whereas “successive contrast” applies when stimuli are presented one after another.4

This distinct is in furtherance of the belief that there are differences that goes beyond the context but into interpretation of what is perceived. As an Empiricist, Locke was committed to the idea that there were no such things as innate ideas and that the best, indeed the only way, to come to know objective truth was via sensory experience.5

As such, the only way to come to know the world is through sensory experience. Locke would agree with the likes of St. Thomas Aquinas that, nothing is in the mind without first having been in the senses. This is to corroborate the idea of that human mind was a blank plate 6; that human sense attracts perception through the five senses.

1.3 Locke’s Account of Sensitive Knowledge

Locke’s monumental Essay Concerning Human Understanding explored the materials and limits of human thinking, setting an agenda those epistemologists like Hume would follow in similarly titled Enquiry. Locke’s Essay is infused with an empiricist spirit, arguing that all our ‘ideas’ that is, the constituents of our thoughts derive from experience, as does every objective knowledge. Having started with a vigorous attack on the theory of ‘innate ideas’, targeting both scholastic and Cartesian attempts to deduce truths by pure reason based on such supposed ideas (as, for example, in Descartes’ argument that the perfection of our innate idea of God implies a perfect cause 8. Locke then goes on to give a thoroughly empiricist account of the origin of our ideas, taking an atomistic approach in which complex ideas are composed of simples, and the simple ideas themselves are directly derived from experience.

Locke defines sensation as a kind of perception, a “perception, which actually accompanies, and is annexed to any impression on the Body, made by an external Object, being distinct from all other Modification of thinking, furnishes the mind with a distinct Idea, which we call sensation” 9 .This experience can be of the external world or of our own minds: thus the senses yield ‘ideas of sensation’ such as the redness of a rose, while introspection yields ‘ideas of reflection’ such as the pain when we touch the rose’s thorn.

Since all such experience is of particular sensations or feelings, the ideas we derive from these are particular also. General ideas (such as the idea of redness in general) then get generated from ideas of particular instances. For example, the colour of different red flowers by ‘abstraction’, in which the differing details for example, the varying brightness are ignored, and notice taken only of what is common to all, leaving an ‘abstract idea’ which is able to represent any instance whatever.

Locke finds that experiences in the world are the vehicles of content. But once we have reached this point, it is natural to wonder whether experience is really playing any essential role in the account of content 10. Surely, anything could serve as a reliable sign of its regular cause. According to Locke, where veridical sensation results in sensitive knowledge, our ideas represent the external world “they represent to us in things,” having a “real conformity” with “things without us” 11.

On a popular reading, the notion of representation at play in veridical sensation involves conformity of resemblance.12 We may then deduce that our ideas are caused by the physical substance; all ideas are mediated by your senses; what causes the ideas is the physical substance that never directly has contact with. While our mental experience is rich with both primary and secondary qualities, the objective world can only be said to possess the primary properties while secondary properties would name subjective experiences only, and not the stuff of serious scientific inquiry or discourse pertaining to objective truth.

However, what Locke intends to relay is somewhat a notion of what we perceive through our five senses. This is the origin of perceptual errors that seem inevitable. Indeed, some of our judgments in physical world are based on our sensory perceptual, they cannot be with certainty as perceptual errors recur perpetually especially in the perception with primary substance. The primary and secondary qualities are differentiated in the ideas that they produce in our mind. These qualities are the power the power that objects have to produce ideas in our mind. The primary qualities of objects will then be the producer of those ideas that resembles the corresponding qualities in the objects that caused us to have those ideas. On the other hand, the secondary qualities of objects produce ideas that do not resemble the corresponding qualities in the object that produced those ideas in our mind.

1.4 Understanding Knowledge of Objects in Locke

The way you decide whether or not a belief is a good belief, that is to say, the way you decide whether a belief is likely to be a genuine case of knowledge is to see whether it is derived from sense experience, to see, for example, whether it bears certain relations to your sensations.13 Just what these relations to our sensations might be is a matter we may leave open, for present purposes. The point is that Locke felt that if a belief is to be credible, it must bear certain relations to the believer’s sensations but he never told us how he happened to arrive at this conclusion. This, of course, is the view that has come to be known as “empiricism.” For Locke there are limits to human understanding and it is important to find out what they are. Fairly certain knowledge is the most reasonable goal of perceptual knowledge and not absolute certainty. The empiricists were looking for a construct of knowledge within the framework of sense data whose aim was to develop a probable hypothesis about the world. However, three major challenges are inevitable;

First, we would deduce the high probability of perceptual error and perceptual relativity, as regular features of everyday life. It is thus unlikely that Locke never noticed their existence. Second, the nature of Locke’s project in the Essay suggests that he must have thought about perceptual error at some point. Locke’s over- arching goal is to delineate “the original, certainty, and extent of human knowledge; together, with the grounds and degrees of belief, opinion, and assent”15. It is surely relevant to that project to examine the circumstances under which we can arrive at true beliefs based on perception and the ways we can tell when we are in such truth- conducive circumstances. Someone who attempts to ground all knowledge and probability in the ideas received through sense should, surely, be concerned with cases where sensory ideas are misleading or false. Third, the tradition Locke wrote and was educated in was intermittently obsessed with perceptual error. Such concern was primarily, although by no means exclusively, connected with the alleged skeptical implications of such error. Works ranging from Descartes’ 1st Meditation to Sextus Empiricus’s Outlines of skepticism discussed standard skeptical tropes involving perceptual error, relativity and disagreement: the straight stick that looks bent in water, for instance, and the water that feels warm to one hand and cool to the other.16 Indeed, Locke himself uses a number of these traditional examples to illustrate or develop17 the distinction between primary qualities and secondary qualities.18

Thus, there is at least, a good reason to think Locke must have considered error and its significance. However, an argument on why Locke might not have considered it comes to mind. Locke might not discuss perceptual error because he thought that doing so would lead to a form of skepticism that is unprofitable and an unworthy subject of philosophical reflection. It is often said that Locke is simply not interested in skepticism, whether of the Pyrrhonian or the Cartesian variety, or that he does not take it seriously.19 Thus, he might think that we should avoid those philosophical topics that give the skeptic a way in. However, it is simply not true that any attempt to address perceptual error would be fodder for the sort of skepticism about the external under Pyrrhonian suspension of judgment about the qualities of things. One might instead, for instance, respond to perceptual error by providing a detailed account of the way that reason can correct the senses or that the senses can correct each other. Alternately, one might discuss perceptual error in strictly naturalistic terms.

Thus, it is implausible that Locke does not discuss perceptual error because he thought any attempt to do so would lead him towards skepticism about the external world or the qualities of the bodies in it.

1.5 Incorporating Ideas in Perceptual Knowledge Analysis

Descartes was the first to do this, when he claimed to perceive clearly and distinctly that the essence of matter was different from that of the thinking self, so that the soul must be immaterial and hence could potentially survive the body’s dissolution. Locke followed, giving an argument for the existence of God which depended on the impossibility of intelligent thought’s arising from the mere primary qualities of matter. However, Locke ventured the opinion that God might, if He wished, to add thought to matter (Essay IV iii 6).20 This provoked a great deal of hostility, since thought was evidently an ‘active’ power, whereas the mechanical philosophy that inspired by the concept of inertia encouraged the idea that matter was purely passive or ‘inert’. Material things were seen as intricate but lifeless machines, their cogs and levers static until set in motion by some external power. This picture would be undermined if a genuinely active power such as thought, or possibly gravity was to be ascribed to matter itself.

Locke is certainly an externalist about content: on his view, simple ideas of perceptions are signs of their regular causes.21 They are signs of external phenomena in something like the way in which smoke is a sign of fire. The immediate problem this raises is that although my ideas are signs of their causes, I do not yet know what any of those causes are like. If all I ever get is smoke, how do I know what fire is like? Any causal correlation view will in the end face some version of this question. How can effects provide you, the subject, with any conception of what their causes are like? This is where Locke introduces his notion of ‘resemblance’22: some ideas, the idea of primary qualities, intrinsically resemble their causes. Those ideas do show what their causes are like. Ideas of secondary qualities, on the other hand, do not resemble their causes. They represent the world perfectly accurately, but they do not show you what the world is like. Now Locke’s notion of resemblance is generally mocked. One possibility is that ‘resembles’ is interpreted in representational terms the world is the way represented in which case it does not get the intended effect; all we have is that the representations are, one way or another, being interpreted so that they come out true. Locke is trying to respect the explanatory role of experience, and merely appealing to it as a bearer of representations does not acknowledge its role in explaining how we can understand such representations. Alternatively, ‘resemblance’ requires that the intrinsic properties of the perceptual idea should be like the intrinsic properties of the object. That is, the intuitively attractive idea at this point in the dialectic.

This knowledge from perception is based on claims that always admit of the possibility that one might be wrong a margin of error may be assigned and the less probable the error, the more probable the claim. It may approach certainty but never achieve certainty. At best, one might claim to know something without having, at the time, any good reason to doubt it.

1.6 Lockean Arguments for Direct Realism

Locke, typically, was more modest, acknowledging that even our scientific understanding of the world is at best ‘probable’ and thus inevitably falls short of the ‘demonstrative’ certainty of mathematics.23Locke on the other hand, will understand his “way of certainty, by the Knowledge of our own Ideas” (IV.iv.2) to require this method of dealing with knowledge of the external world. The distinction of per se and real knowledge thus takes on enormous significance in Locke’s handling of existential knowledge. Although our reason might be fallible and limited, it above all is what elevates us above the other animals. In this, at least, most early modern philosophers could agree with Plato, who saw reason as the central function of the immortal soul, and even Aristotle, who defined man as the one distinctive ‘rational animal’.

Direct or naive realism is a theory of perception that holds that our ordinary perception of physical objects is direct, unmediated by awareness of subjective entities, and that, in normal perceptual conditions, these objects have the properties they appear to have.24 If a fruit tastes sour, the sun looks orange, and the water feels hot, then, if conditions are normal, the pickle is sour, the sun orange, and the water hot. Tastes, sounds, and colours are not in the heads of perceivers; they are qualities of the external objects that are perceived. Although this theory bears the name “naive”, and is often said to be the view of the common person, it need not deny or conflict with scientific accounts of perception. It need only deny that one’s perceptual awareness of objective properties involves an awareness of the properties of subjective (mental) intermediaries.25

For Locke, sense-data are copies (“resemblances”) only of the primary qualities of physical things solidity, extension (in space), shape, and mobility and not of their secondary qualities,26 above all colors, sounds, smells, and tastes. He took the primary qualities to be objective and of the kind that concern physical science; and he considered the secondary ones to be in a sense subjective, not belonging to physical things but something like representational mental elements that they cause in us. Colour, for example then, disappears in the dark, though the physical object causing us to see it is not changed by the absence of light.

Sense-datum theorists like Lockemight offer several reasons to explain why we do not ordinarily notice the indirectness of perception. Here are two important reasons. First, normally what we directly see, say colors and shapes, roughly corresponds to the physical objects we indirectly see by means of what we see directly. It is only when there is an illusion or hallucination that we are forced to notice a discrepancy between what we directly see and the object commonly said to be seen, such as a book. Second, the beliefs we form on the basis of perception are formed spontaneously, not through any process requiring us to consider sense-data. Above all, we do not normally infer what we believe about external objects we see from what we believe about the colors and shapes we directly see. This is why it is easy to think we “just see” things, directly. Perceiving is not inferential, and for that reason (perhaps among others) it is not epistemically indirect, in the sense that knowledge of external objects or beliefs about them are indirect, in the sense that they are based on knowledge of sense-data, or beliefs about them.

On a plausible sense-datum view, I know that the field is green through having rectangular green sense-data, not through inference from propositions about them.27It is apparently true that, as a sense-datum view may allow, perception is not inferential or epistemically indirect in the way inferentiality would imply. But, for sense-datum theorists, perception is nonetheless causally and objectually indirect. The perceived object is presented to us via another object, though not by way of a premise. These theories are causally indirect, then, because they take perceived physical objects to cause sensory experience, say of colors and shapes, by causing the occurrence of sense-data, with which we are directly (and presumably non-causally) acquainted in perceptual experience. Perception is also objectively indirect because we perceive external things, such as fields, through our acquaintance with other objects, namely sense-data.

Roughly, we perceive external things through perceptual acquaintance with internal things. Despite the indirectness of perception in these two respects, a sense datum theorist need not deny that we normally do not use information about sense-data to arrive at perceptual beliefs inferentially, say by an inference from my directly seeing a grassy, green rectangular expanse to the conclusion that a green field is before me. Ordinarily, when I look around, I form beliefs about the external environment and none at all about my sensory experience. That experience causes my perceptual beliefs, but what they are about is the external things I perceive. It is when the colors and shapes do not correspond to the external object, as when a circle appears elliptical, that it seems we can understand our experience only if we suppose that the direct objects of sensory experience are internal and need not match their external, indirect objects. His representative realism states that there is an external world that exists independently of us (that’s the realism part), and we are only indirectly aware of this world, by means of mental representations (that’s the representative part).These representations are generated by your sensory systems, and may be accurate or inaccurate.

1.7 Locke’s Argument on Ideas

Whatsoever the mind perceives in itself, or is the immediate object of perception, thought ,or understanding, that I call idea…28

That is, Locke believes that in “perception, thought, and understanding,” in all forms of conscious awareness, what we are “immediately aware” of are always/only ideas in our minds. The only immediate objects of thoughts, sensations, perceptions, etc. (of any conscious experience) are ideas or sensations, that is, things that exist only in our minds. This is in furtherance of Locke’s dualist stand that mind and matter are two distinct kinds of substances they have nothing in common. Locke’s own view, we can only think about ideas. So, if we can think of material substance at all, it must be an idea. So, material substance is an idea that is not an idea. Locke, believe that there is a world (the material world) that exists independently of whether or not any conscious mind experiences it.29 These forms of dualism imply that our knowledge of physical or material things is derived from our knowledge of the mental or psychical duplicates of physical or material things.

1.8 Summary

I have attempted an analysis of the general conception of perception against the Lockean conception by considering the classical doctrines and operations across disciplines and processes. I went further to discuss Locke’s account of sensitive knowledge. I also characterized perceptual knowledge as analyzed in Lockean epistemology and in relation to object knowledge specifically. The process of incorporating ideas in perceptual knowledge was articulated. I attempted an analysis of Locke’s argument for direct realism with questions on the certainty and uncertainty in mind.


1. Corsini, Raymond J. (2002). “The Dictionary of Psychology”. Psychology Press. p. 219. Retrieved 24 March 2011.

2. Lowe, E.J. Locke on Human Understanding. London: Routledge, 1995.

3. Yolton, John. John Locke and the Compass of Human Understanding. Cambridge: Cambridge University Press, 1970.

4. Fox, Christopher. Locke and the Scriblerians. Berkeley: University of California Press, 1988

5. Lowe, E.J. Locke on Human Understanding. London: Routledge, 1995.

6. Lowe, E.J. Locke on Human Understanding. London: Routledge, 1995.

7. Locke, John. An Essay Concerning Humane Understanding. 1st ed. 1 vols. London: Thomas Bassett, 1690.

8. Rene Descartes, Oeuvres de Descartes, edited by Charles Adam and Paul Tannery (Paris: J. Vrin, 1996), VII.118. Sextus Empiricus, Outlines of scepticism, translated by Julia Annas and Jonathan Barnes (Cambridge: Cambridge University Press, 2000), I.35ff.

9. Mackie, J.L. (1985). Locke and Representative Perception. In J. Mackie and P. Mackie (eds.). Logic and Knowledge: Selected Papers (vol. 1). Oxford: Clarendon Press.p.12

10. Locke, John (2004) An Essay Concerning Human Understanding, Penguin Classics

11. Locke, John (2004) An Essay Concerning Human Understanding, Penguin Classics

12. Hall, R. (1987). Locke and Sensory Experience: Another Look at Simple Ideas of Sensation. Locke Newsletter, 18, 11-31.

13. Hall, R. (1987). Locke and Sensory Experience: Another Look at Simple Ideas of Sensation. Locke Newsletter, 18, 11-31.

14. Glasersfeld, Ernst von (1995), Radical Constructivism: A Way of Knowing and Learning, London: Routledge Falmer; Poerksen, Bernhard (ed.) (2004), The Certainty of Uncertainty: Dialogues Introducing Constructivism, Exeter: Imprint Academic; Wright. Edmond (2005). Narrative, Perception, Language, and Faith, Basingstoke: Palgrave Macmillan.

15. Hall, R. (1987). Locke and Sensory Experience: Another Look at Simple Ideas of Sensation. Locke Newsletter, 18, 11-31.

16. Rene Descartes, Oeuvres de Descartes, edited by Charles Adam and Paul Tannery (Paris: J. Vrin, 1996), VII.118. Sextus Empiricus, Outlines of scepticism, translated by Julia Annas and Jonathan Barnes (Cambridge: Cambridge University Press, 2000), I.35ff.

17. There is some dispute over whether these are meant as arguments for a distinction between primary qualities and secondary qualities or simply as illustrations of that distinction. For the former, see Margaret Atherton, “Ideas in the Mind, Qualities in Body”, in Ideas in Seventeenth Century Philosophy, edited by Philip Cummins and Günter Zoeller (Atascadero, CA: Ridgeview, 1993), 117-118.

For the latter, see Peter Alexander, Ideas, Qualities, and Corpuscles. Cambridge: Cambridge University Press, 1985, 124.

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