E. Uzoigwe, E.I. 2022. A SYNTHESIS OF THE RATIONALIST IDEAS OF PLATO, DESCARTES, SPINOZA, AND LEIBNIZ AND ITS IMPLICATIONS FOR 21ST CENTURY PHILOSOPHICAL DISCOURSE. GPH-International Journal of Social Science and Humanities Research. 5, 07 (Jul. 2022), 27-35. DOI:https://doi.org/10.5281/zenodo.6907010.