Lectures and Essays by the Late William Kingdon Clifford, F.R.S., 第 1 巻

absolutely action aggregate Algiers angles atoms belongs body called character Clifford consciousness consider consists continuous definite Democritus direction distance distinct earth elementary flatness ether Euclid exact exactly exist experience explain fact feelings gases geodesic geometry Herbert Spencer history of eternity hydrogen hypothesis ideas imagine infinite infinite number instant J. S. Mill knowledge lecture light liquid luminiferous ether mathematical matter means ment mind molecules motion move N₁ nature nitrogen observe organism oxygen particles perceive perceptions physical planet position possible postulate present pressure properties quantity question rates of vibration reason retina round scientific thought sensation Sétif side solar system solid space Spinoza statement straight lines strings structure suppose supposition surface temperature theory things tion triangle true universe Unseen Universe velocity vessel whole WILLIAM KINGDON CLIFFORD word