Taken separately, the conditions of Arrow’s theorem do not seem severe. Apparently, they ask of an aggregation procedure only that it will come up with a social preference ordering no matter what everybody prefers (U and SO), that it will resemble certain democratic arrangements in some ways (WP and I), and that it will not resemble certain undemocratic arrangements in another way (D). Taken together, though, these conditions exclude all possibility of deriving social preferences. It is time to consider them more closely. 