Concepts must be consistent and coherent from "summary" of Immanuel Kant: Prolegomena to Any Future Metaphysics by Immanuel Kant
In order for concepts to be of any use in the realm of metaphysics, they must possess certain essential qualities. One such quality is consistency. If a concept is inconsistent, it will inevitably lead to contradictions and confusion, rendering it useless for any meaningful philosophical inquiry. Consistency ensures that a concept is logically sound and free from internal contradictions, allowing for a coherent and systematic development of thought. Furthermore, coherence is another crucial aspect of a concept. A coherent concept is one that fits together smoothly and logically with other concepts, forming a unified and interconnected system of understanding. Without coherence, a concept will be fragmented and disjointed, making it difficult to integrate into a larger philosophical framework. Coherence allows for a seamless flow of ideas and a clear structure of reasoning, enhancing the overall clarity and intelligibility of the concepts under consideration. By maintaining consistency and coherence in their concepts, philosophers can ensure that their ideas are well-founded and rational. This adherence to logical principles and systematic organization of thought is essential for the successful development of a metaphysical theory. Concepts that lack consistency and coherence are bound to be dismissed as incoherent and untenable, failing to contribute meaningfully to the pursuit of metaphysical knowledge.- The requirement for concepts to be consistent and coherent is a fundamental principle that underpins the entire enterprise of metaphysics. Without these essential qualities, concepts lack the necessary logical foundation and interconnectedness to form a coherent and meaningful system of understanding. It is through the rigorous application of consistency and coherence that philosophers can hope to make progress in their exploration of the fundamental nature of reality and existence.
