Nietzsche’s Philosophy: Reason, Truth, Morality, and Science
Reason
The power of knowledge lies in using concepts. But in reality, reason is merely an instrument that human beings use to survive. We use intelligence to try to overcome our weaknesses and, through it, end up believing ourselves to be the center of the universe. Reason, and the language through which it is expressed, therefore create a false picture of reality. This is why Nietzsche criticizes the predominance of conceptual thought in Western philosophy and defends the supremacy of intuition.
Concepts
Concepts are the mental representations through which reason typically interprets reality. A concept (e.g., ‘apple’) can represent a set of individuals (in this example, specific apples) as equal, even though they are genuinely uneven. Thus, equating uneven things builds a fictional reality that serves as a model. For Nietzsche, concepts are merely established metaphors—abstractions useful for our survival, resulting from the generalization of sensory impressions.
Sensitivity
For Nietzsche, reality is in constant evolution, and this can only be grasped by the senses, not by reason. Therefore, the sensible, the apparent, is the only reality, and reason deceives us with its concepts, inventing a transcendent world considered the ‘real’ world. Our knowledge originates and is based on the senses—subtle instruments of observation that faithfully record reality. Only knowledge based on them is scientific. Nietzsche believed he could smell a lie, discover truth with his nose—hence his reference to the nose as a privileged sense.
Truth
Truth, for Nietzsche, is a useful lie for life, a collective illusion, biologically useful for survival, and imposed through use and custom. As lifestyles change over time, so does what is regarded as true in various historical moments.
Morality
For Nietzsche, morals are cultural products originating from different attitudes toward life. Sound and correct morals are life-affirming; sick morals deny life. There are two basic types of morality: the morality of masters and the slave morality. The morality of lords exalts life, the higher type, pride, and self-assertion. The slave morality is the Platonic-Christian morality, through which weak, vulgar men and oppressed classes—slaves—overcome the strong men and values of the old aristocracy.
Plurality
Nietzsche defends the senses as the source of knowledge and denies a unique and immutable reality, opposing traditional epistemology and metaphysics.
Science
For Nietzsche, science should capture the rich diversity of life events and be based on the senses, as they faithfully show us reality. Therefore, fields like metaphysics or theology are not science. Nietzsche also rejects the mathematical model of the mechanistic and positivist science of his time—the science of data and formulas—because it uses concepts (like mass or atom) that are merely false abstractions intended to describe reality. Furthermore, Nietzsche criticizes the supposed progressive nature of positivist science, as it cannot explain life’s fundamentals (love, death, etc.) and thus cannot make value judgments about them. Moreover, positivist science is one of the new idols that have replaced the Judeo-Christian God in function, encouraging flight to an ideal world and serving as an instrument for the state and those in power to perpetuate their privilege.
Causa Sui
The concept of something being the cause of itself (causa sui) is absurd for Nietzsche. In medieval philosophy, this concept typically applied to God, the only being considered without an external cause.