Surprise surprise!

The unexpected hits you between the eyes etc.

Here is an interesting Epicurean argument against divination, found in a scholion to Aesh. Prometh. 624 (Us. 395):

᾿Επικούρειον ἐστι δόγμα ἀναιρῶν τὴν μαντικήν. «εἱμαρμένης γὰρ», φησί, «πάντων κρατούσης πρὸ καιροῦ λελύπηκας †εἰπὼν τὴν συμφορὰν ἢ χρηστόν† τι εἰπὼν τὴν ἡδονὴν ἐξέλυσας». λέγουσι δὲ καὶ τὸ «ἃ δεῖ γενέσθαι, ταῦτα καὶ γενήσεται» 

 There is an Epicurean doctrine that denies divination. Epicurus says: ‘If fate controls everything then when you declare the misfortune then you have been pained before the right moment. Alternatively, if you declare something positive, then you have ruined the pleasure’. These people also say: ‘What has to be will be’. [1] 

It’s quite neat but not convincing. At best it's an argument that divination is something you ought not to do.  If it's not reliable then it is useless.  It it is reliable then it is no benefit.  You go to a fortune teller and ask about your future. If the fortune teller tells you that something bad will happen then this increases your overall distress. Given that the event is fated and therefore inevitable you have simply added the dread of expectation to the eventual pain to come. But if the fortune teller tells you that something good will happen then this ruins the pleasure to come.

I’m interested in this because I am interested in Epicurean attitudes to hope, expectation, and pleasure. The first arm of the dilemma accords well with the claim that prescience or anticipation of an pain merely makes a pain present. This is denied by the Cyrenaics, of course, who think that thinking in advance that an evil will occur may overall lessen the pain of the event. They might have a point, I suppose. 

The second arm, however, seems to run counter to the Epicurean claim that knowledge and expectation of a future pleasure can produce confidence and pleasure in the present. And it doesn’t ring true in any case: unless the fortune teller reveals that your friend has organised a surprise party for you tomorrow and the pleasure of that party should come mostly from the fact that it is a surprise then it seems to me not true that knowing some pleasure will come about will diminish the pleasure. Perhaps we would say it does not diminish the pleasure of the event itself but it might diminish any extra pleasure that might come from its being unexpected. Still, that seems to me to be outweighed by the pleasure you get in the confident expectation of the happy event. Imagine, for example, you are told that you will win big on the lottery next year. (And imagine also that this is a reliable prediction!) Will this make the win any less pleasant? It might make it less of a surprise, for sure, but is that what is pleasant about winning the lottery? 

 [1] Usener prints: εἱμαρμένης γὰρ, φησί, πάντα κρατούσης πρὸ καιροῦ λελύπηκας <εἰπὼν τὴν συμφοράν>, ἢ χρηστόν τι εἰπὼν τὴν ἡδονὴν ἐξέλυσας. 
The line in Aeschylus’ Prometheus Bound is spoken by Prometheus: τὸ μὴ μαθεῖν σοι κρεῖσσον ἢ μαθεῖν τάδε.