I am not sure about the causative form of する verbs.
For example, while reading I found this:
I understand this sentence as:
The mechanism of magicians which let the big source have effect [act] through the small one.
So my guess is that it could be rephrased like this.
Would the meaning change?
And I have troubles with ようにと.
In case the future generations whill "reach" those misteries. Making sure that they will have the basic power to realize that ideal, it's the inheritance accumulated by generations of magicians.
するように=Make sure that
有するように=Make sure to have [Is this correct?]
And why is there と at the end?
Does it stand for と願って、と祈って or such?
Edit. I think that a better translation for
Hoping that they have the basic power to realize [make come true] that ideal, it's the inheritance accumulated by generations of magicians.
Is this right?