epresented his statue, not as constructing space, but as discovering the spatial features that were already present in its sensations from the first. Viewing him as a precursor of 19th century Berkeleyanism risks overlooking this fact and, as a consequence, misrepresenting his thought.
In both the Essay and the Treatise Condillac set out to show that all of our cognitive and conative faculties are generated from sensation and can be derived from that operation alone. To this end he identified perception, consciousness, and attention as all being different aspects of the one operation of sensation. Perception is the impression sensation makes upon the mind, consciousness is this impression considered as something experienced by the mind, and attention is simply a more vivid perception. But when Condillac came to account for memory and reminiscence, this project stalled. It is not implausible to maintain that a sensation might continue to be experienced after the object that occasioned it has ceased to act on the sense organ. But such an “echo” of a past sensation is itself a present phenomenon. It might be fainter than other sensations that are now occurring, but being experienced to be faint is not the same thing as being thought to have originated in the past. Rather than explain how sensation can give rise to an awareness of pastness Condillac simply helped himself to the notion. In the Essay, he defined “reminiscence” as the awareness that a perception has been had “before” without anywhere explaining how the idea that one thing can be “before” another could arise simply from sensation (Essay I.ii.1. §15). In the Treatise he distinguished the memory of a sensation from a current sensation by calling the former “weakly sensing what one was (sentir foiblement ce qu'elle a été)” and the latter “vividly sensing what one is (sentir vivement ce qu'elle est).” But then he immediately went on to say that recalled sensations can sometimes be more vivid than current ones (Treatise I.ii.8–9). So what necessarily distinguishes remembered sensation from current sensation, on this account, is just that remembered sensations are of what “was.” But this is not to explain how we could get the idea that a sensation is of what was as opposed to what is.
Similar difficulties arise in connection with the will. In the Essay, Condillac supposed that the imagination is initially outside of our control. Unless driven by need to conceive the means of achieving an end, we imagine what we do only because in the course of experience we sense accidental or natural signs that suggest particular ideas to us. The use of instituted signs is supposed to change this circumstance and give us a new ability to control our thoughts (Essay I.ii.4.§§45–46). But it is not clear why this should be the case (note, in this regard, the apparent contradiction between Essay I.ii.4. §39 and §46). Just because a being has acquired the ability to produce signs in order to induce thought, it does not follow that this ability must be under the subject's voluntary control, and if the production of instituted signs is outside of our control, it is not clear how their use can give us a power to control our thoughts.
The “sensationist” label notwithstanding, there is some suggestion that Condillac may have taken both memory and volition to be primitive functions of the soul that are not in fact reducible to sensation. In the Essay he described our awareness of the temporal sequence of our perceptions as a “fundamental experience (première expérience)” (Essay I.ii.1. §15) and in the Dissertation on Liberty (§§9–10) he seems to have taken freedom of choice and the ability to spontaneously direct attention to be original abilities that the soul has whenever it is not impelled by some pressing need.
These views of memory and will are not necessarily inconsistent with Condillac's sensationism, his repeated claims to derive all the mind's capacities from the operation of sensation notwithstanding. There are stronger and weaker ways of understanding Condillac's sensationism. On the