Locke, John (1632–1704)

3. Ideas of sensation and reflection: their retention and abstraction

Locke’s employment of the word ‘idea’ responds to a variety of antecedents. Like Descartes, he uses it ambiguously both for representative states (acts, modifications) of mind and, more frequently, for the represented objects as they are represented or conceived of, the so-called ‘immediate’ objects of perception and thought. To have an idea before the mind is generally, for Locke, to be contemplating something under a certain conception rather than contemplating a psychological state. To ‘perceive a relation between ideas’ is to perceive a relation between things-as-conceived-of. But Locke’s account also looks back to the Epicurean view of sensations as signs of their unknown causes in the motion of atoms or ‘corpuscules’ (see §2), a view which points away from the Cartesian and scholastic presumption of intrinsically representative elements in thought towards a purely causal understanding of representation, treating ideas as blank sensory effects in the mind. Locke never resolves the tension between these different conceptions of an idea, although each of them is necessary to his theory.

Locke strongly opposes the Augustinian-Cartesian view that knowledge and truth consist in the conformity of human conceptions with God’s conceptions, the divine ideas or archetypes employed in creation and revealed to us in our active use of reason. For Descartes, human reason is only accidentally involved with the senses, whereas for Locke there are no purely intellectual ideas. The task traditionally assigned to intellect – universal thought – Locke assigns to ‘abstraction’, taken to be the mind’s in some sense separating out elements of raw experience and employing them as ‘standards and representatives’ of a class. What this means will be considered.

Although Locke sometimes writes that all words stand for ideas, ideas are the mental correlates of terms or names: that is, words that can stand in subject or predicate place. He adheres to the traditional view that ‘particles’, such as prepositions, conjunctions, the copula and the negative, signify, not ideas, but ‘the connection that the mind gives to ideas, or propositions, one with another’ (Essay III.vii.1). They do not name, but express ‘actions of the mind in discoursing’: for example, ‘but’ expresses various mental operations together named ‘discretive conjunction’. The mental actions or operations expressed by ‘is’ and ‘is not’ are either the ‘perception of the agreement or disagreement of ideas’, which is Locke’s definition of (at least, general) knowledge, or the ‘presumption’ of such a relation, which is Locke’s account of belief or judgment. As commonly in earlier logic, merely considering a proposition is not distinguished from knowing or judging it to be true.

The aim of Book II of the Essay is to establish that all our ideas derive from experience: that is, that the way we conceive of the world (including ourselves) is ultimately determined by the way we experience the world. ‘Experience’ includes not only ‘sense’, but reflection (’reflexion’) – not reflection in today’s sense but reflexive awareness of our own mental operations. Platonists, Aristotelians and Cartesians all assigned the reflexive awareness of thinking to intellect rather than to sense. For Descartes, the innateness of such ideas as substance, thought and even God consists in the potentiality of their becoming explicit through the mind’s reflecting on itself, and Leibniz argues accordingly that, simply by admitting reflection as well as sense, Locke admits innate ideas (see Leibniz, G.W. §8). Locke, however, claims that reflection, ‘though it be not sense, as having nothing to do with external objects, yet it is very like it, and might properly enough be call’d internal sense’ (Essay II.i.4). Thereafter he treats sense and reflection as theoretically equivalent (although reflexive knowledge of one’s own existence is ‘intuitive’ rather than ‘sensitive’ – Essay IV.ix.3). This move not only extends the empiricist principle to such non-sensory notions as willing, perceiving, contemplation or hope, but also contradicts the Cartesian model of thought as transparent to itself, propounding a gap between how thinking appears to the subject and what it really is in itself – the latter being unknown. Locke also insists that reflection is second-order awareness, presupposing sense-perception as the first mental operation. And though ‘ideas in the intellect are coeval with sensation’ (Essay II.i.23), it seems that the mind must ‘retain and distinguish’ ideas before it can be said to ‘have ideas’ dispositionally, stored in the memory for employment as signifiers in thought. Ideas of reflection in particular are achieved only ‘in time’ – and here ‘reflection’ acquires some of its modern affinity with ‘contemplation’. Children, Locke’s accounts of both reflection and particles imply, can discern or compound ideas without having the ideas of discerning or compounding, and few of those who employ particles to express various mental actions ever pay them enough attention to be able to name them. Locke does assert that in the reception of ideas ‘the understanding is merely passive’, but he also allows that attention, as well as repetition, helps ‘much to the fixing any ideas in the memory’ (Essay II.x.3).

The ‘retention’ of ideas in the memory, therefore, is a necessary condition of discursive thought, and its description significantly echoes Hobbes’ account of memory as ‘decaying sense’. What decay are – ‘it may seem probable’ – images in the brain, and hostility to the separation of intellect from imagination pervades the Essay. Descartes’ famous argument for such a separation – that we can accurately reason about a chiliagon although we cannot form a distinct image of it – is directly rebutted: the reasoning is made possible by our precise idea of the number of the sides (itself dependent on the technique of counting), not by a clear and distinct idea of the shape. ‘Clear’ ideas are, by definition, such as we receive ‘in a well-ordered sensation or perception’. Locke’s treatment of abstraction accords with such express sensationism. ‘Abstract ideas’ are particulars, universal only in ‘the capacity, they are put into…of signifying or representing many particular things’ (Essay III.iii.11). Locke means that in abstract thought the mind relates to, and employs, sensory images in a certain way, not that it manufactures sense-transcendent objects of intellect. Abstract ideas are what we have distinctly before the mind in general thought, but distinctness may be achieved by ‘partial consideration’, not absolute separation: ‘Many ideas require others as necessary to their existence or conception, which are yet very distinct ideas. Motion can neither be, nor be conceived without space’ (Essay II.xiii.11–13). The very abstract ideas of being and unity are ideas of anything whatsoever considered as existing, or as one. Geometry gave Locke his paradigm of ‘perception of the relation between ideas’. But where Cartesians saw the role of geometrical diagrams to be the stimulation of intellectual ideas, for Locke, as for Hobbes, the object of reasoning and source of ‘evidence’ is the diagram itself, whether actual or imagined. (Kant’s ‘intuition’ owes something to Locke.) Given these structural features of his theory, it seems undeniable, as some have denied, that Locke’s ideas are essentially sensory (or reflexive) images (see Hobbes, T. §4; Kant, I. §5).