The trayn of regulated Thoughts is of two kinds; One, when of an effect imagined, wee seek the causes, or means that produce it: and this is common to Man and Beast. The other is, when imaginging any thing whatsoever, wee seek all the possible effects, that can by it be produced; that is to say, we imagine what we can do with it, when wee have it. Of which I have not at any time seen any signe, but in man onely; for this is a curiosity hardly incident to the nature of any living creature that has no other Passion but sensuall, such as are hunger, thirst, lust, and anger. In summe, the Discourse of the Mind, when it is governed by designe, is nothing but Seeking, or the faculty of Invention, which the Latines call Sagacitas, and Solertia; a hunting out of the causes, of some effect, present or past; or of the effects, of some present or past cause. Sometimes a man seeks what he hath lost; and from that place, and time, wherein hee misses it, his mind runs back, from place to place, and time to time, to find where, and when he had it; that is to say, to find some certain, and limited time and place, in which to begin a method of seeking. Again, from thence, his thoughts run over the same places and times, to find what action, or other occasion might make him lose it. This we call Remembrance, or Calling to mind: the Latines call it Reminiscentia, as it were a Re-conning of our former actions.

Thomas Hobbes, Leviathan