Mere conservationists hold that secondary causes are the immediate and per se causes of their effects. They also hold that God’s role in any secondary causal process is only to conserve the existence of the secondary cause allowing it to carry out its own proper effect. Freddoso formulates the three central tenants of mere conservationism as follows:
(CON) Necessarily, for any participated being x and time t such that x exists throughout a temporal interval that includes t but begins before t, God conserves x per se and immediately at t.
(SC) In general, created substances causally contribute both actively and passively to the existence of various entities at various times.
(MC) Necessarily, for any entity x and time t, if any created substance produces x at t as an immediate and per se cause, then God is a (merely) remote cause of x at t and not an immediate and per se cause of x at t. (Freddoso, p.566)
Three arguments from Suarez are presented by Freddoso to show that MC is an unstable position that should be abandoned in favour of a metaphysics that either reserves a larger role for God’s causal influence, viz. concurrentism, or reserves a smaller role, viz. deism (p.567). For our purposes, we will examine only the first of Suarez’s arguments.
Argument One tries to show that CON relies on an ambiguous conception of the term ‘conservation’ that, once clarified, should lead one to reject MC and affirm concurrentism (SC + CON) or reject CON and affirm deism (SC + MC) (p.569). Paraphrasing Freddoso, Suarez’s thought seems to be that in order for CON to do any meaningful dialectical work the notion of ‘conservation’ upon which it relies must apply equally to participated beings in their existence (esse) and in their coming to be (fieri).
Or, as Suarez himself puts it
[T]he existence of a thing cannot depend more on an adequate cause after it has come into existence than it did when it was coming into existence. [DM 22, sec. 1.7] (p.567)
In other words, there is no principled way to draw a metaphysical distinction between the way in which a being depends on God’s conservation for its existence and the way in which it depends upon God’s conservation for its coming into existence.
[I]f it is not the case that all things come to exist immediately from God, then neither is it the case that they are conserved immediately. [DM 22, sec. I.7] (Ibid.)
Thus, we have a dichotomy: either esse and fieri both depend on God’s immediate per se conservation in which case MC is false; or else neither esse nor fieri depend on God’s immediate per se conservation in which case CON is false. Since denying MC leads to concurrentism and denying CON leads to deism, the very possibility of the mere conservationist position (and the persuasiveness of Argument One) depends entirely on whether or not we take the dichotomy that Suarez has set up to be genuine or false.
In the brief space that follows, I want to consider how one might go about arguing that Argument One is based on a false dichotomy.
An argument from reason:
If we take the beliefs of rational beings to count as participated beings then it seems intuitively plausible that the esse of a belief relates to God’s conservation in a different way than does its fieri. For although the existence of the belief — say, that “2+2=4” — depends on God’s immediate conservation in a non-controversial way, it is not at all clear that my coming to believe this fact relies in any way on God’s immediate conservation. Rather, it appears intuitively that my belief, when it is true, follows exclusively from assessment of the reasons I have for believing it. But since the metaphysical status of beliefs in Suarez’s philosophy has not been directly clarified here, this solution can only be preliminary.
 For the purposes of this brief discussion, we can understand ‘participated being’ as any being that is not God.
 All citations refer to Freddoso, Alfred J., “God’s General Concurrence with Secondary Causes: Why Conservation is Not Enough”, Philosophical Perspectives, Vol.5, Philosophy of Religion (1991). pp. 553-585