From the three different versions it will be perceived that this ambiguity must be met (a) by using "that" for "to," which allows us to repeat an auxiliary verb [e.g. "might" in (2)], and (b) by inserting conjunctions. As to insertions of conjunctions, see (37).
"In order to," and "for the purpose of," can be used to distinguish (wherever there is any ambiguity) between an infinitive that expresses a purpose, and an infinitive that does not, e.g. "He told his servant to call upon his friend, to (in order to) give him information about the trains, and not to leave him till he started."
*30. The principle of suspense.* Write your sentence in such a way that, until he has come to the full stop, the reader may feel the sentence to be incomplete. In other words, keep your reader in suspense. Suspense is caused (1) by placing the "if-clause" first, and not last, in a conditional sentence; (2) by placing participles before the words they qualify; (3) by using suspensive conjunctions, e.g. not only, either, partly, on the one hand, in the first place, &c.
The following is an example of an unsuspended sentence. The sense draggles, and it is difficult to keep up one's attention.
"Mr. Pym was looked upon as the man of greatest experience in parliaments, | where he had served very long, | and was always a man of business, | being an officer in the Exchequer, | and of a good reputation generally, | though known to be inclined to the Puritan party; yet not of those furious resolutions (Mod. Eng. so furiously resolved) against the Church as the other leading men were, | and wholly devoted to the Earl of Bedford,—who had nothing of that spirit."
The foregoing sentence might have ended at any one of the eight points marked above. When suspended it becomes:—
"Mr. Pym, owing to his long service in Parliament in the Exchequer, was esteemed above all others for his Parliamentary experience and for his knowledge of business. He had also a good reputation generally; for, though openly favouring the Puritan party, he was closely devoted to the Earl of Bedford, and, like the Earl, had none of the fanatical spirit manifested against the Church by the other leading men."
*30 a. It is a violation of the principle of Suspense to introduce unexpectedly, at the end of a long sentence, some short and unemphatic clause beginning with (a) " … not" or (b) " … which."*
(a) "This reform has already been highly beneficial to all classes of our countrymen, and will, I am persuaded, encourage among us industry, self-dependence, and frugality, and not, as some say, wastefulness."
Write "not, as some say, wastefulness, but industry, self-dependence, and frugality."