According to the first argument, “reason alone can never be a motive to any action of the will” (T 2.3.3.1). Abstract (or demonstrative) reasoning, which involves a priori inferences and judgments pertaining to relations of ideas, cannot influence the will, but only assist us in our pursuit of an end we already have. For example, probable reasoning helps us discover causal relations among objects of experience conducive to the realization of pre-selected ends, but such information about cause an