Alex and Chuck,
I strongly agree on the importance of formal logic, but I must also add that the overwhelming majority of information that we must deal with comes from perception and natural languages. There is no simple, general, dependable, and trustworthy method for mapping those sources to and from any version of logic. 'There are good approximations, but none of them are as precise and dependable as any version of logic.
Chuck's sentence is true about science and technology: "
My hypothesis is that the language of science, technology, and mind is HOL."
But the human mind is far more general than anything that can be mapped to and from HOL by any known or imagined technology that can be processed by any kind of computerized system that is known or proposed or imagined.
In fact, I would add that the reasoning by your pet dog or cat is beyond what can be done with HOL. In fact everybody's favorite nematode C. elegans has only 303 neurons. Scientists have detected and mapped its complete connectome -- every connection of every neuron. But they are unable to predict or simulate its behavior,
There is much more to say about these issues, but there is one serious warning: Any formal ontology about the world is limited by the methods for mapping language and perception to any kind of logic. I sympathize with the concerns that Chuck mentions and links to.
But I am very well aware of the need for serious work on methods of detecting, correcting, and working around the limitations. Anybody who doesn't recognize and include such methods will be doing more harm than good.
That rather short web page has links to many important publications that discuss these issues. I strongly urge people to browse some of them.
John