A proposition counts as true only if its content is so clearly perceived that the will's affirmation cannot be shaken even by the systematic and sustained doubts of the Meditations
A famous book written by philosopher René Descartes in the 1600s where he systematically doubts everything he believes to find what he can be absolutely certain about.
epistemology(Contrasted with purely descriptive scientific inquiry)
A normative enterprise that tells us how we ought to reason from evidence and how we ought to justify our beliefs, as distinct from merely describing how we do reason or justify beliefs
proposition(Used in the context of a semantic theory sensitive to differences in subject matter.)
The content expressed by a sentence, individuated at least in part by the subject matter of the sentence and the contents of its subsentential expressions.
the will(as used in metaphysics and philosophy of mind)
Your desires, drives, and personal goals—basically what you want or need for yourself. In philosophy, 'the will' often refers to this force inside us that pushes us to pursue what we want.
As mentioned in 3.1, Descartes held that any act of judgment, such as the affirmation “I think, therefore I am,” involves both the intellect and will. The intellect perceives or represents the content of the judgment; the will affirms or denies that content. In the face of genuine clarity and distinctness, “a great light in the intellect” is followed by “a great inclination of the will” (7:59). The inclination of the will is so strong that it amounts to compulsion; we cannot help but so affirm.