Mr Osler's remarks, which were notably less hardline than recent statements from Chris Woodhead, his counterpart south of the border, coincided with what he described as "a new and prestigious award".
The Scottish Schools Ethos Network award, named after the recently established initiative of the same name, was announced on Wednesday by Raymond Robertson, the Education Minister. Worth Pounds 2,000 to the winner and Pounds 1,000 to the runner-up, the award aims to promote "a positive approach to learning and teaching". A committee of businessmen, industrialists and educationists will select the winning schools.
Mr Osler, speaking at the first annual conference of the ethos network, was anxious to portray the openness of inspections, backing up schools' assessments of their own worth and the statements of intent in school development plans. But, he warned, such an approach "must not be a comfortable process, a soft option".
Evidence from the Inspectorate showed that development planning was helping schools to manage resources and stay abreast of change. Mr Osler described the process as "a bit like Ronald Reagan's strategic defence initiative: it enables you to view and deal with the onslaught from outside".
He welcomed the addition of promoted teachers to inspection teams and hoped the use of the "associate assessors" could be extended "as a means of moving on the quality thrust. It is also, of course, the ultimate in Inspectorate openness. "
Mr Osler continued: "We hope we will get better and better at using schools' own self-evaluation data in public reports in the future. I would like to see it becoming routine for schools to choose to publish their own assessments of quality, taking account of our performance indicators.
"There is little doubt in my mind that a school's self-evaluation audit will become increasingly important in HMI inspections over the next year or two."
His speech concluded: "Let there be no mistake. The quality initiative in Scotland is unstoppable. It is about sharper and enhanced HMI inspection. It is about thorough, rigorous school self-evaluation. It is about high expectations. It is about raising pupils' performance. It is about a positive school ethos."