The Achaeans at first decided to face the Lacedaemonian single-handed, considering it in the first place most honourable not to owe their safety to others but to protect their cities and country unaided,
and also desiring to maintain their friendship with Ptolemy owing to the obligations they were under to him, and not to appear to him to be seeking aid elsewhere.
But when the war had lasted for some time, and Cleomenes, having overthrown the ancient polity at <a class="linkToPlace" target="_blank" href="/place?placename=Sparta&groupId=660&placeId=1208">Sparta</a> and changed the constitutional kingship into a tyranny, showed great energy and daring in the conduct of the campaign,
Aratus, foreseeing what was likely to happen and dreading the reckless audacity of the Aetolians, determined to be beforehand with them and spoil their plans.
He perceived that Antigonus was a man of energy and sound sense, and that he claimed to be a man of honour, but he knew that kings do not regard anyone as their natural foe or friend, but measure friendship and enmity by the sole standard of expediency.
He therefore decided to approach that monarch and put himself on confidential terms with him, pointing out to him to what the present course of affairs would probably lead.
Now for several reasons he did not think it expedient to do this overtly. In the first place he would thus expect himself to being outbidden in his project by Cleomenes and the Aetolians,
and next he would damage the spirit of the Achaean troops by thus appealing to an enemy and appearing to have entirely abandoned the hopes he had placed in them — this being the very last thing he wished them to think.
Therefore, having formed his plan, he decided to carry it out by covert means.
He was consequently compelled in public both to do and to say many things quite contrary to his real intention, so as to keep his design concealed by creating the exactly opposite impression.
For this reason there are some such matters that he does not even refer to in his Memoirs.
Walbank Commentary