Is Compassion the Nature of Reality?

Yes, according to a passage read to the Lancaster Serene Reflection Meditation Group. However, reality pre-existed consciousness whereas compassion requires it. I suggest that: 
 
someone who is one with reality is compassionate;
therefore, he simultaneously experiences both reality and compassion;
therefore, he tends to identify them, especially if he is influenced by idealist belief in the primacy of consciousness.
 
Meditation on reality shows us our karma (action and consequences) and how to cleanse it. Thus, reality resembles a compassionate teacher but is not a conscious teacher. Although most religions (responses to the highest transcendence) personify or idealise the transcendent, the most basic Buddhist concept is emptiness, not consciousness. "The nature of reality is emptiness" might be more appropriate. The realisation that every subject and object of consciousness is empty of permanent, independent substance may generate compassion for those whose suffering is caused by desire for permanence and fear of impermanence. However, mere emptiness, equally present both in conscious subjects and in unconscious objects, is not itself identical with compassion.

When a group of workers engages in conflict with an employer or manager, any of the workers who practises Buddhist meditation may also practise compassion towards the person with whom they are in conflict but should not let this obscure either the issues involved in the conflict or the need for solidarity with fellow workers whose attitudes may be far from compassionate. Compassion may be a kind of solidarity, with all conscious beings, but, if so, it must be differentiated from solidarity in a more specific sense. Compassion, "suffering with", motivated the Buddha to teach meditation to individuals of all castes whereas class solidarity is a common interest which, when fully realised, will put workers in control of production, thus ending the economic conflict of interest between buyers and sellers of labour power.
 
A Buddhist employer might:

accept pro-capitalist economics, therefore disagree with the political analysis presented here;
reason that the capitalist role, extracting surplus value from living labour, is essentially uncompassionate, therefore cease to be an employer;
reason that we must continue to act within the existing economic system until it is overthrown while avoiding both personal greed and an overtly oppressive or exploitative approach to employees.

Idealism is multifarious:

one conscious being pre-existed matter (theism);
many co-exist with it (Jainism);
the idea of goodness pre-existed instances of goodness (Platonism);
shared ideas, not economic relationships, determine social institutions (common sense);
greed, hate and delusion are beginningless whereas compassion is timeless (Buddhism).

Dialectical materialists, affirming that materially based consciousness generates psychological dispositions and that ideas reflect societies, not vice versa, can value consciousness and compassion without reifying them.
Although Buddhist teaching includes "no soul" and the transience of mental states, it also attributes a perennial robustness to basic motivations. The materialist view is that desire and fear begin anew in each conscious organism and end when the organism dies but that no empirically discernible medium transmits such motives from the last mental state of any dying organism to the first mental state of a particular later organism. The complex of attachments and aversions comprising a human psyche seems to end when the brain dies unless the individual realises enlightenment before death. Between realisation and death, there is consciousness without attachments and aversions. After death, I think, there is neither consciousness nor a potential psyche, unless Spiritualists can prove otherwise.

Barring an ecological catastrophe or thermonuclear war, many people will be born after I have died. Let us consider one of them. He will think of himself as "I", will not remember having been me and will not be regarded as identical with me but can be affected for good or ill by my present actions. These propositions seem to exhaust the entire karmic and moral point of the rebirth teaching. Between my death and that future person's birth, human beings will continue to interact. Some interactions will be direct or indirect effects of my actions. Some will be causes of his birth. It is unlikely that a linear causal sequence will directly link me to him but he and I are indirectly connected as parts of a single empirically discernible reality.

Other, supernatural, realms are the subject matter of religious teachings but are neither verifiably real nor mutually compatible. Catholic priests talk about Heaven, Hell and Purgatory. Zen monks talk about rebirth. Individuals receive these ideas from their traditions, not from their own experience. Catholic practice presupposes Catholic belief whereas Zen practice need not presuppose rebirth. For a Buddhist-materialist synthesis, I suggest recognition of: 
 
the value of meditation;
the possibility of enlightenment;
impermanence;
no soul, but also no rebirth;
materialism that is neither reductive nor mechanical but dialectical and historical.
 
This last aspect incorporates actions that are not only individual and moral but also collective and political. The only negation of traditional Buddhism is "no rebirth" but this is a logical extension from "no soul".