The view of the "behaviourists" is that nothing can be known except by external observation.

It has seemed to the behaviourists that similar methods can be applied to human behaviour, without assuming anything not open to external observation.

Such things as desires and beliefs, which seem obvious to introspection, are not visible directly to external observation.

What exists in us consists of various factors, some open to external observation, others only visible to introspection.

"Define," Adams said, looking up from the rough floor plan that had been worked out from external observation.

I had no light, and might have known by external observation, that the house was without any inhabitant.

In order to pass students must have passed an external observation and one of the 3 internal observations.

The criterion of behavioural change is necessary in order to recognize signals by external observation.

There is one thing, and only one, in the whole universe which we know more about than we could learn from external observation.

After 1998 crisis company got into a difficult financial position, automobile sales dropped significantly, was introduced external observation .