"In order to see how things really are, one must understand the filters through which one perceives the world.".
To properly discuss and evaluate this claim made by German philosopher Immanuel Kant, one must divide the statement into main areas to explore, deconstruct, and reassemble--reality, knowledge, belief, truth, and perception.
There does not exist one all-encompassing reality. Reality, the quality or state of being actual or true, is shaped by a number of factors--mind, environment, and experience. That is to say, reality is not a tool of realism, but of idealism, even phenomenalism; that the external world, the external reality, does not exist without the human mind to shape and interpret it. Phenomenology, a form of philosophical perspective, concerns itself with the idea that, as opposed to positivism, reality is, essentially, relative and subjective--not an objective, singular compilation of facts, data, and records used to form one psychological and physical universe that contains all life. At most, in accordance with the teachings of Plato, though the ultimate reality takes place in Ideas, there is a material reality that resides outside of the human mind.
Kant brought forth the philosophical revolution of transcendental idealism when introducing the serious consideration of the mind's role in building and compiling our knowledge of the objective world, that is, our collections of laws, morals, social structures, facts, and truths. Transcendentalism concerns itself with conditions of possibility, and experience, as opposed to an exploration of the nature of physical existence, and attempts to show us the necessity of our "point of view" on the world as we, or anyone else, know it. According to this idea, the knowledge of things depends upon the ability of the human mind to grasp and form abstract concepts. The knowledge of ding-an-sich ("thing in itself"), or nouema, is impossible to attain.
