Final answer:
A priori knowledge is gained through thinking alone and not based on sense experience, relying on reason and abstract principles such as mathematics and logical deductions.
Step-by-step explanation:
The type of knowledge evident through thinking alone and not based on sense experience is referred to as a priori knowledge. This kind of knowledge is acquired through reason independently of any specific experience. For instance, the mathematical statement that one plus one equals two is an example of a priori knowledge, which relies on abstract reasoning rather than empirical evidence. Similarly, the concept that “I think therefore I am,” as proposed by Descartes, highlights the importance of reasoning and intuition in the acquisition of certain knowledge.
Philosophers like Bertrand Russell have also discussed the distinction between knowledge by acquaintance and propositional knowledge, also known as knowledge by description. The former involves direct cognitive awareness without any inferential process and is a form of a posteriori knowledge. In contrast, truths such as mathematical facts and logical deductions are considered to be forms of a priori knowledge, which can exist independently of sensory experiences.