Strato of Lampsacus (/ˈstreɪtoʊ/; Ancient Greek: Στράτων ὁ Λαμψακηνός, romanized: Strátōn ho Lampsakēnós, c. 335 – c. 269 BCE) was a Peripatetic philosopher, and the third director (scholarch) of the Lyceum after the death of Theophrastus.

[1] He attended Aristotle's school in Athens, after which he went to Egypt as tutor to Ptolemy II, where he also taught Aristarchus of Samos.

[2] Cicero, while speaking highly of his talents, blames him for neglecting the most important part of philosophy, that which concerns virtue and morals, and giving himself up to the investigation of nature.

[3] In the long list of his works, given by Diogenes Laërtius, several of the titles are upon subjects of moral philosophy, but the great majority belong to the department of physical science.

Strato emphasized the need for exact research,[4] and, as an example of this, he made use of the observation of how water pouring from a spout breaks into separate droplets as evidence that falling bodies accelerate.

[4] Strato believed all matter consisted of tiny particles, but he rejected Democritus' theory of empty space.

[15]Like the atomists (Leucippus and Democritus) before him, Strato of Lampsacus was a materialist and believed that everything in the universe was composed of matter and energy.

[17] As quoted from Charles Lyell's Principles of Geology: Strabo passes on to the hypothesis of Strato, the natural philosopher, who had observed that the quantity of mud brought down by rivers into the Euxine was so great, that its bed must be gradually raised, while the rivers still continued to pour in an undiminished quantity of water.

He therefore conceived that, originally, when the Euxine was an inland sea, its level had by this means become so much elevated that it burst its barrier near Byzantium, and formed a communication with the Propontis, and this partial drainage had already, he supposed, converted the left side into marshy ground, and that, at last, the whole would be choked up with soil.

[18] Also following the reference of Georgius Agricola Strato of Lampsacus, the successor of Theophrastus, wrote a book on the subject of metallic arts called De Machinis Metallicis.

[26] This Aristarchus had a significant impact on philosophers and scientists during the Hellenistic era of philosophy and science, and also later scholars, namely Copernicus and Kepler.