Medicine, economic reform and Buddhism address aspects of suffering. Suffering can occur only because consciousness exists. Consciousness is a by-product of natural selection. For mobile organisms, pleasure and pain have greater survival value than merely unconscious sensitivity to environmental alterations. For conscious beings, consciousness is not a by-product of another activity but an end in itself. However, conscious beings are the only kind of beings that can have ends in this sense.
"Mind" means either intellect in particular or consciousness in general. In the general sense, we contrast, for example, the "mind" of an ant with that of a man and Buddhists mean by "Buddha Mind" the faculty of intuitive wisdom, not of intellectual comprehension. Meditation discloses, first, that mind in general is not a visible, tangible object and, secondly, that its states are even less permanent than those of external objects. Mental states succeed each other with great rapidity. This reflects their physical basis. Organisms maintain their form actively, not passively. They continually change their composition by exchanging matter with their environments. Cells change their states as bodies adjust to environmental alterations. Multiple brain cell linkages change while processing changing sensory inputs and respond differently according to their past experience.
Mental flux reflects this psychophysical flux. Not mere complexity but complex organism-environment interaction generates consciousness and action on the environment generated human consciousness. Increasing complexity causes mental suffering by adding memories, anticipations and imaginings to immediate sensations. Buddhists seek the cause and end of suffering within. On different levels, Buddhists and Marxists see and do what needs to be done without requesting questionable divine help.
Zen meditation is not practised in discrete stages but Zen trainees might experience: the transience of mental states; the tendency of thought to perpetuate them; the emergence of deeper dissatisfactions like guilt or resentment. We need to heed problematic feelings when they arise but not to perpetuate them by thinking about them at other times. In this case, our thinking about how to solve the problem is the problem. Heeding guilt etc means not thinking about it but watching it arise and pass. What matters is not the passing mental states but the awareness through which they pass like clouds through the sky. That awareness is the way to the end of suffering.