Sophisticated people nowadays use 'emergence' to 'explain' complex phenomena (e.g. systems comprising many agents) - especially when they do not want to posit any innate purpose, or do not believe in the existence of such purpose.
So, in describing a biological organism or sub-system, they might regard it as emergent from simpler units such as cells - a consequence of what just happens, spontaneously, when many specialist cells gather together, perhaps combined with some kind of mathematical tendency for 'order', or a selection process.
The idea is that there is no originating centre to the purpose; but instead apparent purpose emerges-from dispersed interactions from an innate, pattern-generating tendency.
Emergence is sometimes used to explain (or explain-away) the apparent cohesion and purposiveness, working across many subunits and across time, of phenomena that are seen in human society - such as the economy, war, or the mass media. Emergence is therefore contrasted with the focused purposiveness of top-down, hierarchical, organized, teleological beings...
I emphasize 'beings' as providing and imposing cohesion and purpose on a society, because of the common assumption that it can only come from humans. But that is another assumption - I mean the assumption that exists no God nor other supernatural beings, and therefore there can be no divine or other supernatural purposes at work in human society.
For example, the evil tendency of modern Western institutions is regarded first of all as neither divine nor supernatural (because they do not exist - by assumption).
Having restricted possible explanations to the human, the choice is between humans working in a centralized and hierarchical manner to impose cohesion and purpose - and the rival idea that order and direction emerge-from the nature of systems; and do not require positing any central and coordinating purpose.
By this account, evil Just Happens when systems (of the kind we currently have) emerge...
But emergence is not an explanation on the same level as the phenomena it purports to explain. Emergence is not some kind of scientific discovery. It is not some kind of solid, observable, empirical datum.
Instead; 'emergence' is simply a hypothetical assumption that some particular observation can and does happen without any guiding purpose or organization.
The advocate of emergence as an explanation has made unacknowledged metaphysical exclusions (e.g. of God and the supernatural as possible explanations), and is then making the unacknowledged metaphysical assumption that there is such-a-thing as emergence.
Having already-assumed that 'emergence' is real and can explain the phenomenon under discussion; then it is regarded as the preferred explanation on the grounds of some other general assumption about how to make valid decisions.
This might be along the lines of 'Occam's Razor' - which assumes that the simplest explanation (i.e. which excludes by assumption the largest number of possible causes) is true; or it least pragmatically preferable.
Another common assumption about how to make decisions is that we should always prefer to blame 'cock-ups' rather than 'conspiracies' - but this is not a generalizable empirical principle, nor is it logically justifiable; it is merely a modern (and often maladaptive) prejudice.
Yet even as a way of choosing between explanations; this modern procedure is rooted in some historically strange ideas about what counts as a simple explanation.
Through most of history (and probably still in most of the world) the most obvious - and thus simple - explanation is that things happen because some-one, or some-being, wants them to happen and made them happen.
When simple people encounter what looks-like coordination, control and purpose; they spontaneously have tended to assume that this is because some individual (or some cohesive group) is doing it - and that they want it because their nature is to want that kind of thing.
The place we have arrived at now is based upon layer upon layer of denying what is spontaneously obvious to simple humans; until we have reached the situation where the simple obvious explanation is the only thing we absolutely refuse to believe.
And because we refuse to believe the obvious, we cannot even perceive the obvious.
So, modern people cannot perceive evil purpose - cannot perceive personalized, organized and directional action towards evil - because they do not believe in God and therefore have no coherent understanding of evil.
Thus any apparent evil, pursued across nations and through decades, cannot actually be the work of beings with evil natures; but instead must be an 'emergent property' of abstract systems.
And this 'must be'; simply because all other possible explanations have already been ruled-out, in advance, by multiple unacknowledged prior metaphysical assumptions.