The question of whether a posteriori knowledge is the only type of knowledge humans can have is a complex philosophical issue with different perspectives. It's important to recognize that both a priori and a posteriori knowledge contribute to human understanding and knowledge acquisition in different ways.
A priori knowledge refers to knowledge that is independent of experience or observation, often relying on reasoning and logic. For example, mathematical truths and certain logical propositions are considered a priori knowledge.
A posteriori knowledge refers to knowledge that is gained through experience, observation, or empirical evidence. This type of knowledge is derived from sensory perceptions and interactions with the external world.