An absolutist ethics/morality is one that considers something immoral regardless of consequence, situation, and circumstance. Even if something has negative/positive consequence, and even if something is done under duress and out of necessity, this something is immoral without exception. That's what I refer to when using the term absolutist morality. For instance, say lying is always immoral. Theft is always immoral. Etc, etc. I've been told absolutist morality is lazy. How can the absolutist position be defended? ...
One perhaps obvious argument would be executive efficiency, which is essentially the cause behind using heuristics in general. A system, whether a single brain or a whole society, which has substantially limited executive capacity or otherwise which requires fast turnover, could easily benefit from using heuristics such as simple, absolute rules. The result may not be ideal or fair for special cases, but it would likely be systemically efficient.
An example statement from this position might be:
We cannot afford to waste time on special cases.
I've been told absolutist morality is lazy
In a way that makes sense.
I suppose arguments for absolutism hinge on our intuitive beliefs that some things are immoral independent of any states of affairs, as well as problems with moral relativism:
a metaethical thesis that the truth or justification of moral judgments is not absolute, but relative to the moral standard of some person or group of persons
Note that in some sense all the great meta ethical theories are absolute: even act consequentialism says that we should always perform the action with the best consequences. Indeed I suspect you are asking about deontology, looking for deontological proscriptions which hold dependent upon consequences. But sadly that would be nothing at all in the spirit of it, so I'd guess you should just read amore about act consequentialism
The paradigm example of a Consequentialist ethics, Classical Utilitarianism, is also a perfect example of Absolutism: any action which maximizes pleasure or happiness is right and good absolutely, whatever else may be the case.
Absolutism v consequentialism: no contest Don Locke Analysis, Volume 41, Issue 2, April 1981, Pages 101–106,