He allowed himself to think that it would be possible to arrive at an alphabet of nature, which, once attained, would suffice to spell out and constitute all its infinite combinations.

He accepted, without thinking it worth a doubt, the doctrine of appetites and passions and inclinations and dislikes and horrors in inorganic nature.
His whole physiology of life and death depends on a doctrine of animal spirits, of which he traces the operations and qualities as if they were as certain as the nerves or the blood, and of which he gives this account--"that in every tangible body there is a spirit covered and enveloped in the grosser body;" "not a virtue, not an energy, not an actuality, nor any such idle matter, but a body thin and invisible, and yet having place and dimension, and real." ...

"a middle nature between flame, which is momentary, and air which is permanent." Yet these are the very things for which he holds up Aristotle and the Scholastics and the Italian speculators to reprobation and scorn.

The clearness of his thinking was often overlaid by the immense profusion of decorative material which his meditation brought along with it.

The defect was greater than that which even his ablest defenders admit.