这句是对上句的延伸，其实Idea更可能是三种解释（概念，法则及理想）的集合。

Very probably the Idea is all of these — idea, law and ideal.
很可能，理念是集三者于一体，既是概念，也是法则，还是理想。

细节解析

1、all of these — idea, law and ideal
“— idea, law and ideal”是“all of these”的同位结构，补充说明these。

所在段落

The Story of Philosophy《哲学的故事》第1章Plato第7节VI. The Psychological Solution第14段第3句：

But this famous doctrine of Ideas, embellished and obscured by the fancy and poetry of Plato, is a discouraging maze to the modern student, and must have offered another severe test to the survivors of many siftings. The Idea of thing might be the "general idea" of the class to which it belongs (the Idea of John, or Dick, or Harry, is Man); or it might be the law or laws according to which the thing operates (the Idea of John would be the reduction of all his behavior to "natural laws"); or it might be the perfect purpose and ideal towards which the thing and its class may develop (the Idea of John is the John of Utopia). Very probably the Idea is all of these — idea, law and ideal. Behind the surface phenomena and particulars which greet our senses, are generalizations, regularities, and directions of development, unperceived by sensation but conceived by reason and thought. These ideas, laws and ideals are more permanent — and therefore more "real" — than the sense-perceived particular things through which we conceive and deduce them: Man is more permanent than Tom, or Dick, or Harry; this circle is born with the movement of my pencil and dies under the attrition of my eraser, but the conception Circle goes on forever. This tree stands, and that tree falls; but the laws which determine what bodies shall fall, and when, and how, were without beginning, are now, and ever shall be, without end. There is, as the gentle Spinoza would say, a world of things perceived by sense, and a world of laws inferred by thought; we do not see the law of inverse squares but it is there, and everywhere; it was before anything began, and will survive when all the world of things is a finished tale. Here is a bridge: the sense perceives concrete and iron to a hundred million tons; but the mathematician sees, with the mind's eye, the daring and delicate adjustment of all this mass of material to the laws of mechanics and mathematics and engineering, those laws according to which all good bridges that are made must be made; if the mathematician be also a poet, he will see these laws upholding the bridge; if the laws were violated the bridge would collapse into the stream beneath; the laws are the God that holds up the bridge in the hollow of his hand. Aristotle hints something of this when he says that by Ideas Plato meant what Pythagoras meant by "number" when he taught that this is a world of numbers (meaning presumably that the world is ruled by mathematical constancies and regularities). Plutarch tells us that according to Plato "God always geometries"; or, as Spinoza puts the same thought, God and the universal laws of structure and operation are one and the same reality. To Plato, as to Bertrand Russell, mathematics is therefore the indispensable prelude to philosophy, and its highest form; over the doors of his Academy Plato placed, Dantesquely, these words, "Let no man ignorant of geometry enter here."16
16The details of the argument for the interpretation here given of the doctrine of Ideas may be followed in D.G. Ritchie's Plato, Edinburgh, 1902, especially pp.49 and 85.
浙江大学译本： 更有可能的是，理念是以上这些方面的集合体—概念、规则和理想。

上句见：Day412