Photography and engraving.
Has photography done more to popularize art than engraving? Is photography of greater importance than engraving? Matson, p. 368: Briefs and references.
Physical force and mind force. See [Mind force and physical force.]
Planets.
Is it probable that the planets or other heavenly bodies are inhabited? Matson, p. 410: Briefs and references.
Plato and Aristotle.
Is Plato a greater philosopher than Aristotle? Is the philosophy of Plato, on the whole, superior to that of Aristotle? Matson, p. 425: Briefs and references.
Plato and Socrates.
Is philosophy as much indebted to Socrates as to Plato? Should Socrates be held in as high estimation as Plato? Matson, p. 423: Briefs and references.
Plural voting. See [Ballot.]