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Gentle Power: A Revolution in How We Think, Lead, and Succeed Using the Finnish Art of Sisu!


Power is fundamental in our lives―we express it in every conversation, relationship, and choice we make. All too often, we equate force and domination with power, while gentleness and compassion are considered “soft” or “weak.” The destructive nature of this skewed perspective has never been more obvious, yet there is reason to hope.


"With Gentle Power, Lahti shares an illuminating guide to an emerging shift in the way we define true strength―an approach that balances resolve with reason, grit with compassion, and personal success with service to the collective good." - Sounds True 

Gentle Power is available at bookstores across the U.S. and at Amazon. In Finland and Sweden, you can oder yours at Adlibris.




Can Finns Teach the World to Hang Tough?



An In-depth
Personal Interview

(in Finnish)


Insider 2014

The Untranslatable


Les Affaires

Comment Tirer du Positif à Partir Du Négatif?

(in French)

Aalto University

PhD: Sisu as guts grace and gentleness: A way of life growth and being in times of adversity (2022)

Business Insider

Leaders Should use 'Gentle Power' to Unite and Encourage Teams During Uncertain Times



Sisu &

Mental Toughness

BBC World

Sisu: The Finnish Art of

Inner Strength



Want to Achieve Your Goals? The Finns Have a Word for That



What the Finnish Concept of Sisu, or Inner Strength, Can Teach Us

Psychology Today


An Ultramarathon Runner's Secret to Mental Toughness

Aalto University


Research paper press release: What Finnish Sisu Can Offer the World (2019)


Positiivisen psykologian voima I


The Finnish Educational Textbook

on Positive Psychology


This best-selling textbook is one of the primary educational resources for Positive Psychology in Finland. The book consists of 16 chapters incl. topics such as positive pedagogy, workflow, mindfulness, a critique of positive psychology, strengths in aging, happiness vs. meaning, as well as a chapter entitled "Sisu - An Action Mindset" (incl. sisu within communities, post-traumatic growth, and relationship between adversity and well-being.

Order Positiivisen psykologian voima I as a hard copy here.

Sisu: Tarinoita itsensä ylittämisestä

ja hyvän tekemisestä


The Finnish Book on Sisu


This book shares the stories of Finnish people from all walks of life as they overcome adversity, use creativity to transform barriers into frontiers, and take action against all odds. 

It outlines a message of hope in tough times and shows us that there is always more to us than meets the eye. One way to remember this inner fortitude within us is through witnessing and celebrating the inspirational stories of all the many sisuesque humans in our world.

Order Sisu: Tarinoita itsensä ylittämisestä ja yhdessä tekemisestä as a hard copy here.


Business Insider

Leaders Should use 'Gentle Power' to Unite and Encourage Teams During Uncertain Times

Positive Psychologists 

on Positive Psychology


Interviews with the

Field's Leading Practitioners

Our Words Make 

Worlds: Introducing Sisu

Summary of Sisu

and its Early-stage research

Brilliance of a Dream:

Introducing the Action Mindset


An Introduction to

Action Mindset

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