Quotations about:
    juggling

It is impossible, either in action or in thought, to attend to two things at once, especially if they are of any importance.

[Duas tamen res, magnas praesertim, non modo agere uno tempore, sed ne cogitando quidem explicare quisquam potest.]

Marcus Tullius Cicero (106-43 BC) Roman orator, statesman, philosopher

Philippics [Philippicae; Antonian Orations], No. 11, ch. 9 / sec. 23 (11.9/11.23) (43-02 BC) [ed. Harbottle (1906)]
    (Source)

(Source (Latin)). Other translations:

But still no man can, I will not say do two things, especially two most important things, at one time, but he can not even do entire justice to them both in his thoughts.
[tr. Yonge (1903)]

But two things, above all, two great ones, no man can, I do not say, transact at the same time, but even think out with clearness.
[tr. Ker (Loeb) (1926)]

Yet two affairs, especially great, nobody can drive simultaneously, nor even disentangle in the mind.
[tr. Wiseman]