VERBS, AUXILIARY. Should denotes contingent futurityShould. Should is the past tense of shall, and underwent the same modifications of meaning as shall. Hence should is not now used with the second person to denote mere futurity, since it suggests a notion, if not of compulsion, at least of bounden duty. But in a conditional phrase, "If you should refuse," there can be no suspicion of compulsion. We therefore retain this use of should in the conditional clause, but use would in the consequent clause:
If you should refuse, you would do wrong.On the other hand, Shakespeare used should in both clauses:
And should is frequently thus used to denote contingent futurity.
“You should refuse to perform your father's will if you should
refuse to accept him.
"Would" = "were in the habit." Comp. ἐφίλουν.
“They told me here, at dead time of the night,
Ten thousand swelling toads, as many urchins,
Would make such fearful and confused cries,
As any mortal body hearing it
Should straight fall mad.
“(In that case) Strength should be lord of imbecility,
And the rude son should strike the father dead;
Force should be right.