thoughts. This point was now taken up by Carneades, who, in attempting to establish the conditions and degrees of probability, hoped to obtain a clue to the kind of conviction which might be still permitted in his system. However much we may despair of knowledge, some stimulus and groundwork for action is needed. Certain things must therefore be assumed, from which the pursuit of happiness must start. [1500] To these so much weight must be attached that they are allowed to decide our conduct, but we must be on our guard against considering them to be true, or to be something really known and conceived. Nor must we forget that even the nature of true ideas is similar to that of false ones, and that the truth of ideas can never be known with certainty. Hence we should withhold all assent, not allowing any ideas to be true, but only to have the appearance of truth (ἀληθῆ φαίνεσθαι) or probability (ἔμφασις, πιθανότης). [1501] In every notion two things need to be considered, the relation to the object represented which makes it either true or false, and the relation to the subject who has the notion, which makes it seem either true or false. The former relation is, for the reasons already quoted, quite beyond the compass of our judgment; the latter, the relation of a notion to ourselves, falls within the sphere of consciousness. [1502] So long as a notion seemingly true is cloudy and indistinct, like an object contemplated from a distance, it makes no great impression on us. When, on the contrary, the appearance of truth is strong, it produces in us a belief [1503] strong enough to determine us to action, although it does not come up to the impregnable certainty of knowledge. [1504]