[Side-note: Sensation, obscure knowledge relative to the sentient; Thought, genuine knowledge--absolute, or object per se.] Hence Demokritus termed sensation, _obscure knowledge_--thought, _genuine knowledge_.[238] It was only by thought (reason, intelligence) that the fundamental realities of nature, atoms and vacua, could be apprehended: even by thought, however, only imperfectly, since there was always more or less of subjective movements and conditions, which partially clouded the pure objective apprehension--and since the atoms themselves were in perpetual movement, as well as inseparably mingled one with another. Under such obstructions, Demokritus proclaimed that no clear or certain knowledge was attainable: that the sensible objects, which men believed to be absolute realities, were only phenomenal and relative to us,--while the atoms and vacua, the true existences or things in themselves, could scarce ever be known as they were:[239] that truth was hidden in an abyss, and out of our reach. [Footnote 238: Demokritus Fragm. Mullach, p. 205, 206; ap. Sext. Empir. adv. Mathemat. vii. 135-139, [Greek: gnô/mês du/o ei)si\n i)de/ai; ê( me\n gnêsi/ê, ê( de\ skoti/ê], &c.] [Footnote 239: Democr. Frag., Mull., p. 204-5. [Greek: A(/per nomi/zetai me\n ei)=nai kai\ doxa/zetai ta\ ai)sthêta/, _ou)k e)/sti de\ kata\ a)lê/theian tau=ta;_ a)lla\ ta\ a)/toma mo/non kai\ keno/n. ê(me/es de\ tô=| me\n e)o/nti ou)de\n a)treke\s xuni/emen, meta/pipton de\ kata/ te sô/matos diathigê/n, kai\ tô=n e)peisio/ntôn, kai\ tô=n a)ntistêrizo/ntôn . . . . e)teê=| me/n nun, o(/ti oi(/on e(/kasto/n e)stin ê)\ ou)/k e)stin, ou) xuni/emen, pollachê= dedê/lôtai], &c. Compare Cicero, Acad. Quæst. i. 13, ii. 10; Diog. Laert. ix. 72; Aristotel. Metaphys. iii. 5, p. 1009, b. 10.] [Side-note: Idola or images were thrown off from objects, which determined the tone of thoughts, feelings, dreams, divinations, &c.]