Ancient Philosophy

Problems of Knowledge

The doctrine of being in ancient philosophers is inextricably linked to their conception of knowledge. Agnosticism is not characteristic of ancient philosophy. Indeed, during the Hellenistic-Roman period of ancient thought, skepticism emerged, founded by Pyrrho. However, skepticism is not agnosticism in the true sense of the term. Skepticism, while trusting the senses and noting the variability of perceptions and impressions, taught one to refrain from judgments about the true essence of things. "Do not determine anything, do not agree with anything," is the motto of skepticism.

The overwhelming majority of ancient philosophers do not share the skeptical position and recognize the unconditional knowability of the world. Yet their conception of the goal of knowledge, and consequently of the process of knowing itself, significantly differs from modern notions. Ancient philosophy perceives the aim of knowledge not as the understanding of mutable sensory-objective reality, but rather as grasping that which lies beyond it, which conditions its very existence, remaining eternally self-identical, in the knowledge of the One. Thus, philosophy is regarded by the Greeks as the highest science; it is through it that one can attain the One, the primal source. Knowledge found in other sciences (in ancient Greece, we encounter the beginnings of history through Herodotus and Thucydides, medicine through Hippocrates and Galen, mathematics through Pythagoras and Euclid, physics through Democritus and Archimedes, astronomy through Ptolemy and Aristarchus with his heliocentric system) is merely a more or less reliable opinion. Greek philosophers, especially in the pre-classical and classical periods, clearly differentiate the outcomes of knowledge into knowledge and opinion.

This understanding of the goal of knowledge and the essence of knowledge itself shapes a peculiar interpretation of the process of knowing. Greek philosophers recognized that humans possess two instruments, two means of knowledge—sensation and intellect. However, their roles in the process of knowing are diverse. According to ancient philosophers, sensory knowledge cannot provide us with true understanding; it can only serve as a source of opinion. This can be explained. The One, the primal source, cannot be seen, heard, or felt. Even Democritus, who views the process of knowledge as an emanation from objects through intermediary atoms affecting the senses, thus forming images within us, believes that truth is accessible only to the intellect. For the atoms that constitute the essence of things are so minuscule that they cannot be perceived by the senses, but only by the mind. Truly, he declares, only atoms and the void exist; color, taste, and smell exist merely in thought.

But how can we know the primal source, the One, the universal, if sensory perception cannot provide us with an understanding of it, if the intellect cannot rely on sensory data? To some extent, the answer to this question is provided by Plato’s theory of knowledge. According to Plato, knowledge is reminiscence. The true world, as discussed previously, is the world of ideas, and it is the goal of knowledge. This goal is achieved through the soul, which, before being imprisoned in the body (the image of the body as the soul's prison is not a Christian but an ancient metaphor), resided in the world of ideas and was capable of contemplating them. Now, it need only recall what it has seen. "Since the soul is immortal," Plato writes in the dialogue "Meno," "often reincarnates and has seen everything both here and in Hades, there is nothing it has not known; therefore, it is not surprising that it can remember what was once familiar regarding virtue and all else."

Aristotle attempts to overcome the opposition between sensory and intellectual knowledge. This arises from his doctrine of being. For Aristotle, substance refers to individual objects and species. Species, as forms, constitute the essence of things, present within them as a formative principle. Knowledge begins with sensory perception of specific objects, but the goal of knowledge is to grasp species or forms, achieved through abstraction from sensory-concrete objects. However, he is not entirely consistent on this matter. In the "Metaphysics," while reflecting on the intellect, Aristotle asserts that the highest form of thought cannot be about objects. "The intellect thinks itself, if it is the highest, and its thinking is thinking about thinking." "To be thought and to be that which is comprehended by thought are not the same. But is knowledge not sometimes the subject of knowledge? In knowledge of creativity, the object is the essence taken without matter, and in intuitive knowledge, it is definition and thought. Therefore, since what is comprehended by thought and the intellect do not differ in that they lack matter, they will be one and the same, and thought will be unified with what is understood by thought." Thus, Aristotle believes that true knowledge is associated with thought. Imaginative knowledge is accessible only through thought—this is the fundamental conclusion of ancient philosophy concerning knowledge. The ability to think is inherent in humans because they are creations of the Cosmos, which also thinks and possesses a soul. This encapsulates the distinctive nature of ancient understanding not only of knowledge but also of humanity.