From Pope St. John Paul II’s encyclical Fides et Ratio (1984):
Nonetheless, it is true that a single term [viz., philosophy] conceals a variety of meanings. Hence the need for a preliminary clarification. Driven by the desire to discover the ultimate truth of existence, human beings seek to acquire those universal elements of knowledge which enable them to understand themselves better and to advance in their own self-realization. These fundamental elements of knowledge spring from the wonder awakened in them by the contemplation of creation: human beings are astonished to discover themselves as part of the world, in a relationship with others like them, all sharing a common destiny. Here begins, then, the journey which will lead them to discover ever new frontiers of knowledge. Without wonder, men and women would lapse into deadening routine and little by little would become incapable of a life which is genuinely personal.
Through philosophy’s work, the ability to speculate which is proper to the human intellect produces a rigorous mode of thought; and then in turn, through the logical coherence of the affirmations made and the organic unity of their content, it produces a systematic body of knowledge. In different cultural contexts and at different times, this process has yielded results which have produced genuine systems of thought. Yet often enough in history this has brought with it the temptation to identify one single stream with the whole of philosophy. In such cases, we are clearly dealing with a “philosophical pride” which seeks to present its own partial and imperfect view as the complete reading of all reality. In effect, every philosophical system, while it should always be respected in its wholeness, without any instrumentalization, must still recognize the primacy of philosophical enquiry, from which it stems and which it ought loyally to serve.
Although times change and knowledge increases, it is possible to discern a core of philosophical insight within the history of thought as a whole. Consider, for example, the principles of non-contradiction, finality and causality, as well as the concept of the person as a free and intelligent subject, with the capacity to know God, truth and goodness. Consider as well certain fundamental moral norms which are shared by all. These are among the indications that, beyond different schools of thought, there exists a body of knowledge which may be judged a kind of spiritual heritage of humanity. It is as if we had come upon an implicit philosophy, as a result of which all feel that they possess these principles, albeit in a general and unreflective way. Precisely because it is shared in some measure by all, this knowledge should serve as a kind of reference-point for the different philosophical schools. Once reason successfully intuits and formulates the first universal principles of being and correctly draws from them conclusions which are coherent both logically and ethically, then it may be called right reason or, as the ancients called it, orthós logos, recta ratio.
— Fides et Ratio 4
