The text presented here, a letter that accompagnied the gift of an astrolabe, was sent to Pylaemenes, an important military leader whom Synesius had met in Constantinople. It is a brief essay in which Synesius advises politicians to study the sciences (which the author, as always, calls "philosophy"). Synesius also mentions several improvements to the instrument; the model sent to Pylaemenes appears to have been some sort of prototype.
The text is offered in the translation by A. Fitzgerald.
On an Astrolabe 1-8
 I heard you recently expressing indignation on behalf of philosophy, and asking whether there could be any limit to the impiety of men towards it, again lamenting that it had encountered evil and harsh fortune, for that those who falsely pretend knowledge of it, by their continual charlatanism enjoy a good reputation with the ruling class and the people alike. But the true philosophers are discredited, and are honored only with the Carian portion.note[A despicably small portion.]
 I admired your outburst, for it proceeded from a really noble nature. For all that, one need not be angry when what is only logical is taking place, and it is quite logical that every man should attain what he has busied himself with, and worked for, and again should not attain those things the which he never struggled for, nor took thought how they might be his. If therefore, one man has set his mind on becoming wise, and another upon only seeming so, each one will possess that which befits him, the one in being wise, the other in merely appearing to be wise. Now truly, they would suffer grievously - those who are in pursuit of a reputation for the false, not the real philosophy - and would indeed be quite justly angered, if those who desired the other kind should be found in possession of both, and they themselves in possession of neither! And this in spite of the fact that they have cultivated the easier thing with no less care than their rivals, in order to deceive those who know nothing of the very matters in which they are deceived. Let such men, accordingly, be shining lights, let them be crowned in the theaters if they so desire; for having been deserters from the cause of Truth, they are disputing over its name only.
 Now as to us, who are of but slight importance, it is evident that you desire to include me amongst the elect, and it was largely on my account that you were so incensed at the present state of philosophy. Treated though we are, therefore, with disregard by other men, we should nevertheless be pleased at the rank into which we have been marshaled by ourselves. Let us not be envious of these half-instructed ones, nor esteem them happy when they are praised to the skies by those who have no education whatever, for they who are not purified may not see the beauty of the purified soul, and the heralding abroad of oneself and the doing of all things for display is the part not of wisdom but of sophistry. Wherefore it may be properly said by those who share not in such honor as the multitude can confer, "I need not this honor, but I seek to be honored by the destiny of Zeus",note[Homer, Iliad 9.608.] to rejoice and be of great joy that I have met with a man who possesses both sagacity and power, for thus only shall we not be counted with the unworthy, nor be esteemed utterly without honor.
 How shall I fail to keep the most intimate spot in my heart for the admirable Paeonius, he who has found means of restoring and binding to each other philosophy and military science, so long walled away from each other by many ramparts, and has detected the affinity which aforetime existed between these pursuits!
 For when Italy in bygone days possessed the same men as pupils of Pythagoras and governors of cities, it was called Magna Graecia, and rightly so. Of these men Charondas and Zaleucus gave laws, the Archytae and the Philolai were masters of the field. The greatest of astronomers ruled over a city, and was an ambassador, besides taking other parts in political life, Timaeus himself, on whose authority Plato discourses to us concerning the universe. Having been entrusted with these communities, as late as the ninth generation after Pythagoras they preserved Italy in prosperity, and as to the Eleatic School at Athens, letters and arms were pursued by it with equal honor for both.
 In the case of Zeno you would find it difficult to enumerate how many tyrannies he destroyed, always reinstating in their place a healthy form of city government. Again, Xenophon taking command of those ten thousand, exhausted by sufferings and almost at the point of death, led them back from utmost confines of the Persian Empire, overcoming every obstacle in his way.
 And what can one say of this? - the succession of Dionnote[The story is told here.] to the monarchy of Dionysius, that kingdom which had enslaved the Greek cities in Sicily, those not the least in respect to power, and also the barbarians. Even the will of the Carthaginians it bent, and it gained ground even on the coast of Italy. Nay, it was against that kingdom that the lover and beloved of Plato collected a mercenary army and set sail for Sicily, embarking his whole fighting force on a single ship, and that a merchantman; and it was with such an equipment as this that Dionysius was driven out, and that Dion transformed the constitution, and restored the cities to the reign of law.
 Thus, in the past, philosophy and statecraft were united, and when they so went hand in hand, such were their achievements. But, as in the case of other fair and hallowed things, with all of which Time has worked havoc, this double type, too, forsook the succeeding age, and separation of the function was reserved for posterity. Surely it is not worth while to dwell on the destinies of man. Is it not for this very reason that other good things also have deserted us? For no greater misfortune could possibly befall cities than to have strength without intelligence, and intellect without power.