They reject dialectic as superfluous; holding that in their inquiries the physicists should be content to employ the ordinary terms for things.An opinion often emphasized: e.g.§§ 37, 73, 82, 152. Cf. Lucr. iii. 931 sqq.Now in Epicurus affirms that our sensations and preconceptions and our feelings are the standards of truth; the Epicureans generally make perceptions of mental presentationsSuch mental pictures are caused by atoms too fine to affect sense: cf.§ 64infra; Lucr. ii. 740 sqq., iv. 722 sqq.; Cic. i. 54. On the whole subject consult Usener’s , Fr. 242-265, and, more especially, Sext. Emp. vii. 203-216. to be also standards. His own statements are also to be found in the addressed to Herodotus and in the Every sensation, he says, is devoid of reason and incapable of memory; for neither is it self-caused nor, regarded as having an external cause, can it add anything thereto or take anything therefrom. Nor is there anything which can refute sensations or convict them of error: