542 Proceedings of the Royal Society 
to promulgate the theory of our perceiving all things in G-od. It 
also prompted Leibnitz to maintain that there was no operative 
connection between the mind and external physical nature, but 
merely a pre-established harmony ; and much the same difficulty 
led Berkeley to deny the existence of an external world, and to 
declare that our perceptions were not real, but only apparent, 
being mere ideas evoked in the mind by Deity. 
Reid and Stewart also represented perception in the light of an 
inexplicable miracle, on which the study of the physical laws not 
only threw no light, but rather served to mislead and pervert the 
inquirer. The Deity they held to be the only efficient cause in 
perception. 
Mr Wyld holds that the difficulty thus experienced by philoso- 
phers disappears the moment we carefully examine the physical 
phenomena. Thus in the sensations of light and sound, it is not 
matter or substance which affects us, but it is the force or power 
transmitted by the respective media , which affects the mind. Force 
or power Mr Wyld defines to be the action of an unseen immaterial 
agent, as proved in his former paper on “ Free Transmissible 
Power.” And wherever movement is observed to exist, we have 
evidence of the existence of force as its cause. 
When we explore, says Mr Wyld, the links of cause and effect in 
the physical world, and also when we contemplate the operations 
of the mind, we are made aware that the seen and the unseen, the 
physical and the mental, rest alike on the spiritual foundation of 
power. Power is the immaterial or spiritual element in nature — 
that which produces and governs every physical phenomena ; it is 
the copula uniting cause and effect. It is also the attribute of 
the active principle within us, by which we feel, and think, and 
move, and exercise control over external nature. 
Reduced, then, to a philosophical form, we stand in this position : 
It is the power of the Supreme Being which constitutes the energies 
and forces of nature. These forces act on the mind, and the mind, 
as a real agent, acts on them. Our intercourse with nature thus 
strictly implies a connection of mind with mind, — the connection 
of the Great Mind with his creatures ; not, however, as maintained 
by Malebranche, Berkeley, Leibnitz, or Reid, by miraculous inter- 
position or action, but, on the contrary, expressly by and through 
