Abductive inference, as defined by Charles S. Peirce, involves (1) observation of a surprising fact, (2) formulating (guessing) a proposition which, if true, would explain this fact as a matter of course, (3) and provisional acceptance of the proposition as true, (4) leading to its being taken as a premise for subsequent deduction, the consequences of which will then be related to further observations via induction-surprises from which can then trigger new abductive inferences, and so forth. Peirce limited this process to human reasoning because he viewed thought as a semiosis (flow of signs) continuous between the human mind and the world, such that (1) the human subject is in thought, as opposed to thought being in the subject, and that (2) there is an intrinsic ability of human beings to "guess right" as a consequence of this continuity of mind and world. The challenge posed by this view of thinking is that, unlike a human subject, any vehicle for autonomous reasoning is a newly created object that is separate from the world. It cannot be what Martin Heidegger termed a "being-in-the-world" because of the artificial separation of its thought from the world viewed as semiosis.