But Hobbes, Spinoza, and Leibniz, were most attentively heard in the passages where they favoured or combatted the dominant social and theological prepossessions. Their glimpses of truer insight and even their palpable contributions in the line of a true psychology were ignored or forgotten. More attention, perhaps, was attracted by an attempt of a very different style. This was the system of Condillac, who, as Hegel says (p. 61), made an unmistakable attempt to show the necessary interconnexion of the several modes of mental activity. In his _Traité des Sensations_ (1754), following on his _Essai sur l’origine des connaissances humaines_ (1746), he tried to carry out systematically the deduction or derivation of all our ideas from sense, or to trace the filiation of all our faculties from sensation. Given a mind with no other power than sensibility, the problem is to show how it acquires all its other faculties. Let us then suppose a sentient animal to which is offered a single sensation, or one sensation standing out above the others. In such circumstances the sensation “becomes” (_devient_) attention: or a sensation “is” (_est_) attention, either because it is alone, or because it is more lively than all the rest. Again: before such a being, let us set two sensations: to perceive or feel (_apercevoir ou sentir_) the two sensations is the same thing (_c’est la même chose_). If one of the sensations is not present, but a sensation made already, then to perceive it is memory. Memory, then, is only “transformed sensation” (_sensation transformée_). Further, suppose we attend to both ideas, this is “the same thing” as to compare them. And to compare them we must see difference or resemblance. This is judgment. “Thus sensation becomes successively attention, comparison, judgment.” And—by further steps of the equating process—it appears that sensation again “becomes” an act of reflection. And the same may be said of imagination and reasoning: all are transformed sensations. If this is so with the intelligence, it is equally the case with the Will. To feel and not feel well or ill is impossible. Coupling then this feeling of pleasure or pain with the sensation and its transformations, we get the series of phases ranging from desire, to passion, hope, will. “Desire is only the action of the same faculties as are attributed to the understanding.” A lively desire is a passion: a desire, accompanied with a belief that nothing stands in its way, is a volition. But combine these affective with the intellectual processes already noticed, and you have thinking (_penser_)(40). Thus thought in its entirety is, only and always, transformed sensation.