GOD entrails of sacriWced animals, by the interpretation of dreams, and by the consultation of oracles Not all of these modes of divination are fashionable in the modern world, but Cicero’s consideration of astrology is still, sadly, relevant Quintus heaps up anecdotes of remarkable predictions by augurs, soothsayers, and the like, and argues that in principle they are acting no diVerently from the rest of us when we predict the weather from the behaviour of birds and frogs or the copiousness of berries on bushes In both cases we not know the reason that links sign and signiWed, but we know that there is one, just as when someone throws double sixes a hundred times in succession we know it is not pure chance Not all soothsayers’ predictions come true: but then doctors too make mistakes from time to time We may not understand how they make their predictions, but then we don’t understand the operation of the magnet either (D 86) Quintus conWrms his empirical evidence with an a priori argument drawn from the Stoics If the gods know the future, and not tell it to us, then they not love us, or they think such knowledge will be useless, or they are powerless to communicate with us But each of these alternatives is absurd They must know the future, since the future is what they themselves decree So they must communicate the future to us, and they must give us the power to understand the communication: and that power is the art of divination (D 82–3) Belief in divination is not superstitious but scientiWc, because it goes hand in hand with the acceptance of a single united series of interconnected causes It is that series that the Stoics call Fate (D 125–6) Marcus Cicero begins his reply in a down-to-earth manner If you want to know what colour a thing is, you had better ask somebody sighted rather than a blind seer like Tiresias If you a sick, call a doctor, not a soothsayer If you want cosmology, you should go to a physicist, and if you want moral advice, seek a philosopher, not a diviner If you want a weather forecast trust a pilot rather than a prophet If an event is a genuine matter of chance, then it cannot be foretold, for in chance cases there is no equivalent of the causal series that enables astronomers to predict eclipses (D 15) On the other hand, if future events are fated, then foreknowledge of a future disaster will not enable one to avoid it, and the gods are kinder to keep such knowledge 309