Next to Locke, Descartes and Malebranche are prominent in the _Principles_. Recognition of the ultimate supremacy of Spirit, or the spiritual character of active power and the constant agency of God in nature, suggested by Descartes, was congenial to Berkeley, but he was opposed to the mechanical conception of the universe found in the Cartesian physical treatises. That thought is synonymous with existence is a formula with which the French philosopher might make him familiar, as well as with the assumption that _ideas only_ are immediate objects of human perception; an assumption in which Descartes was followed by Locke, and philosophical thinkers in the seventeenth and eighteenth centuries, but under differing interpretations of the term _idea_. Malebranche appears less in the _Principles_ than Locke and Descartes. In early life, at any rate, Berkeley would be less at home in the “divine vision” of Malebranche than among the “ideas” of Locke. The mysticism of the _Recherche de la Vérité_ is unlike the transparent lucidity of Berkeley’s juvenile thought. But the subordinate place and office of the material world in Malebranche’s system, and his conception of power as wholly spiritual, approached the New Principles of Berkeley. Plato and Aristotle hardly appear, either by name or as characteristic influence, in the book of _Principles_, which in this respect contrasts with the abundant references to ancient and mediaeval thinkers in _Siris_, and to a less extent in the _De Motu_ and _Alciphron_. ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐