Synesius of Cyrene (c.370-c.413) was a Neo-Platonic philosopher who became bishop of Ptolemais in the Cyrenaica. He left behind a small corpus of texts that offer much information about daily life in Late Antiquity, and about the christianization of the Roman world.
Synesius' On dreams consists of two parts:
- A philosophical explanation why dreams allow our soul to reach higher spheres, based on a doctrine that is derived from the philosophical school known as Stoa (sections1-7);
- A more down-to-earth, and very accessible, account of the way one must investigate one's dreams, which boils down to keeping a "night book"(section 8-13).
The text is offered here in the translation by A. Fitzgerald. The four-digit numbers are page numbers of the Migne edition.
Synesius, On dreams 8
 We shall pray for a dream, even as Homer, perchance, prayed. And if you are worthy, the god far away is present with you. Nay, even what time the god sets little store on these matters, he comes to your side if only you are asleep; and this is the whole system of the initiation. In it no one has ever yet lamented his poverty, on the ground that thus he had less possession than the rich. On the other hand, some of the ceremonies which deal with foreknowledge choose their priests from the most heavily assessed as the Athenians choose their trierarchs. And great expense there must needs be, and, no less, happy opportunity, if we are to obtain a Cretan herb, an Egyptian feather, an Iberian bone, and, by Zeus, some prodigy begotten and nourished in a hidden corner of earth and sea,
Where that the sun god sinks 'neath the earth and where he arises.note[Homer, Odyssey 1.24.]
 For surely this and much like it is said of those who practice external divination, and what ordinary person would be right enough for this out of his own resources? But the dream is visible to the man who is worth five hundred medimni, and equally to the possessor of three hundred, to the teamster no less than to the peasant who tills the boundary land for a livelihood, to the galleyslave and the common laborer alike, to the exempted and to the payer of taxes.  It makes no difference to the god whether a man is an eteoboutades or a newly-bought slave.
 And this accessibility to all makes divination very humane; for its simple and artless character is worthy of a philosopher, and its freedom from violence gives it sanctity. That it is present everywhere and does not employ water or rock or a chasm in the earth, is its most divine quality, and that through divination of this sort we do not become occupied with one matter only, or lose opportunities through it, this also is the first thing worthy to say of it.
 For surely no one every left any important matter he might have in hand, to go home to sleep, to meet a dream by appointment. Time, however, which the living being must spend of his nature, inasmuch as our being in the waking state is insufficient to the support of its energy, time, I say, has come to convey to men, as the proverb has it, "the by-work which is greater than the work," for it links the desirable with the inevitable and well-being with being itself.
 As to these forms of foreknowledge, on the other hand, which come to us through all manner of instruments, we must be content if, having occupied the greater part of life, they make some concession to its remaining needs and activities. If you were to give yourself up to any of these things, you would scarcely find divination of use to you for your purpose, for it is not every place or every season in which one can receive the equipment for the initiation, nor is there every facility for carrying about with you the necessary implements. To speak nothing else but those things which the prisons were lately congested, they are loads for a wagon or a ship's hold. Combined with this there were other elements in the initiation, namely registrars and witnesses. For this would be a more accurate statement, since our time has made many denunciations through those who serve the laws, by whom once betrayed, such initiations become matters for the gaze and the hearing of an unholy mob.
 Thus, in addition to the baseness of stooping to such practices, it is, I am persuaded, a course hateful to the god. For not to await voluntarily any one's coming, but to set him moving by pressure and leverage, this is like the employment of force, a thing which even when it has happened among men, the legislator has not allowed to pass unpunished. In addition to all these points, difficult enough to those who seek after the future in this way, there is also the chance of interruption of their activity, and to those who go abroad, the abandonment of the art; for it is no small matter, when moving everywhere, to pack and convey the properties necessary for its practice.
 Of divination by dreams, each one of us is perforce his own instrument, so much so that it is not possible to desert our oracle there even if we so desired. Nay, even if we remain at home, she dwells with us; if we go abroad she accompanies us; she is with us on the field of battle, she is at our side in the life of the city; she labors with us in the fields and barters with us in the market place. The laws of a malicious government do not forbid her, nor would they have the power to do so, even if they wished, for they have no proof against those who invoke her. For how then? Should we be violating the law by sleeping? A tyrant could never enjoin us not to gaze into dreams, at least not unless he actually banished sleep from his kingdom; and it would be the act of a fool to wish for that which is impossible of fulfillment, and of an impious man to make laws which should be contrary to nature and to God.
 To her then we must go, woman and man of us, young and old, poor and rich alike, the artisan and the orator. She repudiates neither race, nor age, nor condition, nor calling. She is present to every one, everywhere, this zealous prophetess,  this wise counselor, who holdeth her peace. She herself is alike initiator and initiated, to announce to us good tidings; in such wise as to prolong our pleasure by seizing joy beforehand; to inform against the worst so as to guard against and repel it beforehand.
 For whatsoever things of use and of sweetness those hopes, which nourish the race of men,note[Sophocles, Fragment 862 [Nauck].] hold out to him, and as many things as fear controls, things ominous and withal gainful, all these things are found in dreams, nor by any other thing are we so enticed towards hope. And the element of hope is so abundant and so salutary in its nature, that, as acute thinkers maintain, men would not even be willing to continue life, if it were only to be such as they had at the beginning. For they would forswear life by reason of the terrible misfortunes abounding therein, had not Prometheus injected hopes into their nature, that drug of constancy, under the influence of which they esteem the anticipated to be more worthy of trust than that which is before their eyes. And these hopes have such force that he who is bound in fetters, whenever he permits the will of his heart to hope, is straightway unbound. He enters the army, straightway becomes a lieutenant, after a little, a captain. He then becomes a general, makes conquests, and sacrifices to the gods; his head crowned with garlands, he gives a banquet, a Sicilian or a Median, as he pleases; and in truth he is forgetful of his feet as long as he dreams of being a general.
 Now all of this is the waking state of the dreamer, or the sleeping state of the awakened, for both are concentrated upon the same underlying state, to wit the imaginative nature, and whenever we wish to convert this into images, this one benefit is always at hand; good cheer anoints our life and, flattering our soul with illusive hopes, lifts it aloft from the perception of things ill to be borne. And when it spontaneously presents hope to us, as happens in our sleeping state, then we have in the promise of our dreams a pledge from the divinity. Thus any one who has prepared his mind to enjoy those greater things which the dream state held out to him, has twice profited, for the first thing he had delighted in the things beforehand, and that secondly he is in a position to use them wisely, when they have come his way, because of his previous examination of them, as things which befit his life.
 Thus Pindar praised hope in song, when he said concerning a happy man that
with him liveth sweet hope, the nurse of youth,
the fosterer of his heart, hope who chiefly ruleth
the changeful mind of man.note[Pindar, Fragment 214 [Schroeder].]
 One would say that no allusion is made here to the false hope which in a waking state we mold for ourselves, but all the words of Pindar in this passage are praises of only a small part of dreams. Now the divination of dreams which follows up the phenomenon with scientific methods gives us a stronger hope, and from this it seems not to belong to the slighter class. And so the Penelope of Homer assumes that there are two gates of dreams, and makes half of them deceptive dreams, only because she was not instructed in the matter. For if she had been versed in their science, she would have made them all pass out through the gate of horn. As it is, she has been represented guilty of ignorance about her very sight, for she distrusted it without reason.
The geese are the wooers, and I that bird, the eagle, I am Odysseus.note[Homer, Odyssey 19.548.]
 He was under the same roof as she, and it was to him that she was babbling in the vision. I seem, therefore, to hear Homer say in such words as these, that it is not right to despair of dreams, and that we should not confuse the weakness of the interpreter with the nature of the visions themselves, nor is Agamemnon in the right when he beings a charge of deception against dreams, for he erroneously interprets the prophecy concerning the victory:
Bade thee call them up to arms the flowing-haired, the Achaeans,
Summoning all their force: thou mayst capture the wide-wayed city.note[Homer, Iliad 2.11-12.]
 He advances indeed to take the city without striking a blow, because he has misinterpreted the phrase, "with all their forces," which means that he might take it, if he armed all the Greeks, even to the last man, whereas Achilles and the Myrmidon phalanx were out of the fighting, and they were the bravest of the army.
Let this suffice for my encomium on divination, and let us dismiss the subject.